Item 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued

STATEMENTS OF CONSOLIDATED STOCKHOLDERS' EQUITY

(in millions)			Common Stock						Preferred Stock**(1)**						Treasury Stock						Additional Paid-In Capital						Retained Deficit						Accumulated Other Comprehensive Loss						Noncontrolling Interest in Consolidated Subsidiaries						Total
Balance as of December 31, 2022			$	4.2					$	1,546.5					$	(99.9)					$	7,375.3					$	(1,213.6)					$	(37.1)					$	326.4					$	7,901.8
Comprehensive Income:
Net Income (Loss)			—						—						—						—						714.3						—						(39.9)						674.4
Other comprehensive income, net of tax			—						—						—						—						—						3.5						—						3.5
Dividends:
Common stock ($1.00 per share)			—						—						—						—						(414.1)						—						—						(414.1)
Preferred stock (See Note 6)			—						—						—						—						(43.8)						—						—						(43.8)
Noncontrolling Interests:
Issuance of noncontrolling interests(2)			—						—						—						809.6						—						—						1,361.1						2,170.7
Contributions from noncontrolling interest (3)			—						—						—						—						—						—						233.2						233.2
Distributions to noncontrolling interest			—						—						—						—						—						—						(14.1)						(14.1)
Stock issuances (redemptions):
Equity Units			0.3						(666.5)						—						666.2						—						—						—						—
Series A Preferred stock redemption			—						(393.9)						—						—						—						—						—						(393.9)
Series A Preferred stock redemption premium			—						—						—						—						(9.8)						—						—						(9.8)
Employee stock purchase plan			—						—						—						5.9						—						—						—						5.9
Long-term incentive plan			—						—						—						12.6						—						—						—						12.6
401(k) and profit sharing			—						—						—						9.9						—						—						—						9.9
Balance as of December 31, 2023			$	4.5					$	486.1					$	(99.9)					$	8,879.5					$	(967.0)					$	(33.6)					$	1,866.7					$	10,136.3
Comprehensive Income:
Net Income			—						—						—						—						760.4						—						84.3						844.7
Other comprehensive income, net of tax			—						—						—						—						—						3.2						—						3.2
Dividends:
Common stock ($1.06 per share)			—						—						—						—						(483.0)						—						—						(483.0)
Preferred stock (See Note 6)			—						—						—						—						(8.1)						—						—						(8.1)
Noncontrolling Interests:
Contributions from noncontrolling interest(3)			—						—						—						—						—						—						99.5						99.5
Distributions to noncontrolling interest			—						—						—						—						—						—						(66.4)						(66.4)
Stock issuances (redemptions):
Series B and B-1 Preferred stock redemption			—						(486.1)						—						—						—						—						—						(486.1)
Series B and B-1 Preferred stock redemption premium			—						—						—						—						(14.0)						—						—						(14.0)
Employee stock purchase plan			—						—						—						6.4						—						—						—						6.4
Long-term incentive plan			—						—						—						26.6						—						—						—						26.6
401(k) and profit sharing			—						—						—						9.2						—						—						—						9.2
ATM Program			0.2						—						—						599.8						—						—						—						600.0
Balance as of December 31, 2024			$	4.7					$	—					$	(99.9)					$	9,521.5					$	(711.7)					$	(30.4)					$	1,984.1					$	10,668.3
Comprehensive Income:
Net Income			—						—						—						—						929.5						—						83.1						1,012.6
Other comprehensive income, net of tax			—						—						—						—						—						24.2						—						24.2
Dividends:
Common stock ($1.12 per share)			—						—						—						—						(533.0)						—						—						(533.0)
Noncontrolling Interests:
Contributions from noncontrolling interest(3)			—						—						—						—						—						—						231.4						231.4
Distributions to noncontrolling interests			—						—						—						—						—						—						(88.8)						(88.8)
Stock issuances (redemptions):
Employee stock purchase plan			—						—						—						7.4						—						—						—						7.4
Long-term incentive plan			—						—						—						30.2						—						—						—						30.2
401(k) and profit sharing			—						—						—						9.4						—						—						—						9.4
ATM Program			0.1						—						—						298.1						—						—						—						298.2
Balance as of December 31, 2025			$	4.8					$	—					$	(99.9)					$	9,866.6					$	(315.2)					$	(6.2)					$	2,209.8					$	11,659.9

(1) Series A, Series B and Series C shares had an aggregate liquidation preference of $400M, $500M and $863M, respectively.

(2) Relates to the NIPSCO Minority Interest Transaction. See Note 4, "Noncontrolling Interests," for additional discussion.

(3) Contributions from NIPSCO and GenCo (starting in 2025) minority interest holders included in noncontrolling interest is net of transaction costs.

The accompanying Notes to Consolidated Financial Statements are an integral part of these statements.

NIS****OURCE **INC.**ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)

STATEMENTS OF CONSOLIDATED STOCKHOLDERS’ EQUITY (continued)

			Preferred						Common
(in thousands)			Shares						Shares						Treasury						Outstanding
Balance as of December 31, 2022			1,303						416,106						(3,963)						412,143
Issued:
Employee stock purchase plan			—						216						—						216
Long-term incentive plan			—						758						—						758
401(k) and profit sharing plan			—						366						—						366
Equity Units(1)			—						33,899						—						33,899
Redeemed:
Equity Units(1)			(863)						—						—						—
Series A Preferred Stock			(400)						—						—						—
Balance as of December 31, 2023			40						451,345						(3,963)						447,382
Issued:
Employee stock purchase plan			—						218						—						218
Long-term incentive plan			—						769						—						769
401(k) and profit sharing plan			—						309						—						309
ATM Program			—						21,144						—						21,144
Redeemed:
Series B and B-1 Preferred Stock			(40)						—						—						—
Balance as of December 31, 2024			—						473,785						(3,963)						469,822
Issued:
Employee stock purchase plan			—						186						—						186
Long-term incentive plan			—						772						—						772
401(k) and profit sharing plan			—						231						—						231
ATM Program			—						7,421						—						7,421
Balance as of December 31, 2025			—						482,395						(3,963)						478,432

(1)See Note 6, "Equity," for additional information.

The accompanying Notes to Consolidated Financial Statements are an integral part of these statements.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

1. Nature of Operations and Summary of Significant Accounting Policies

A. Company Structure and Principles of Consolidation. We are an energy holding company incorporated in Delaware and headquartered in Merrillville, Indiana. Our subsidiaries are fully regulated natural gas and electric utility companies serving approximately 3.8 million customers in six states. We generate substantially all of our operating income through these rate-regulated businesses. The consolidated financial statements include the accounts of us, our majority-owned subsidiaries, and VIEs of which we are the primary beneficiary after the elimination of all intercompany accounts and transactions.

B. Use of Estimates. The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements, and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.

C. Cash, Cash Equivalents and Restricted Cash. We consider all highly liquid investments with original maturities of three months or less to be cash equivalents. We report amounts deposited in brokerage accounts for margin requirements as restricted cash. In addition, we have amounts deposited in trusts to satisfy requirements for the provision of various property, liability, workers compensation, and long-term disability insurance, and holdbacks related to certain joint venture development agreements which is classified as restricted cash on the Consolidated Balance Sheets and disclosed with cash and cash equivalents on the Statements of Consolidated Cash Flows.

D. Accounts Receivable and Unbilled Revenue. Accounts receivable on the Consolidated Balance Sheets includes both billed and unbilled amounts. Unbilled amounts of accounts receivable relate to a portion of a customer’s consumption of gas or electricity from their last cycle billing date through the last day of the month (balance sheet date). Factors taken into consideration when estimating unbilled revenue include historical usage, customer rates, weather and reasonable and supportable forecasts. Accounts receivable fluctuates from year to year depending in large part on weather impacts and price volatility. Our accounts receivable on the Consolidated Balance Sheets include unbilled revenue, less reserves. The reserve for uncollectible receivables is our best estimate of the amount of probable credit losses in the existing accounts receivable. We determined the reserve based on historical collection experience, current market conditions and reasonable and supportable forecasts. Account balances are charged against the allowance when it is anticipated the receivable will not be recovered. Refer to Note 3, "Revenue Recognition," for additional information on customer-related accounts receivable, including amounts related to unbilled revenues.

E. Investments in Debt Securities. Our investments in debt securities are carried at fair value and are designated as available-for-sale. These investments are included within “Available-for-sale debt securities” and "Other investments" on the Consolidated Balance Sheets. Unrealized gains and losses, net of deferred income taxes, are recorded to accumulated other comprehensive income or loss. At each reporting period these investments are qualitatively and quantitatively assessed to determine whether a decline in fair value below the amortized cost basis has resulted from a credit loss or other factors. Impairments related to credit loss are recorded through an allowance for credit losses. Impairments that are not related to credit losses are included in other comprehensive income and are reflected in the Statements of Consolidated Income. No material impairment charges were recorded for the years ended December 31, 2025, 2024 or 2023. Refer to Note 14, "Fair Value," for additional information.

F. Basis of Accounting for Rate-Regulated Subsidiaries. Rate-regulated subsidiaries account for and report assets and liabilities consistent with the economic effect of the way in which regulators establish rates, if the rates established are designed to recover the costs of providing the regulated service and it is probable that such rates can be billed and collected. Certain expenses and credits subject to utility regulation or rate determination that would normally be reflected in income for non-regulated entities are deferred on the Consolidated Balance Sheets and are later recognized in income as the related amounts are included in customer rates and recovered from or refunded to customers.

We continually evaluate whether or not our operations are within the scope of ASC 980 and rate regulations. As part of that analysis, we evaluate probability of recovery for our regulatory assets. In management’s opinion, our regulated subsidiaries will be subject to regulatory accounting for the foreseeable future. Refer to Note 12, "Regulatory Matters," for additional information.

G. Plant and Other Property and Related Depreciation and Maintenance. Property, plant and equipment (principally utility plant) is stated at cost. Our rate-regulated subsidiaries record depreciation using composite rates on a straight-line basis over the remaining service lives of the electric, gas and common properties, as approved by the appropriate regulators.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Non-utility property, consisting of renewable generation assets owned by JVs of which we are the primary beneficiary and certain retired regulatory assets described below, is generally depreciated over the life of the associated assets. Refer to Note 9, "Property, Plant and Equipment," for additional information related to depreciation expense.

For rate-regulated companies where provided for in rates, AFUDC is capitalized on all classes of property except organization costs, land, autos, office equipment, tools and other general property purchases. The allowance is applied to construction costs for that period of time between the date of the expenditure and the date on which such project is placed in service. Our consolidated pre-tax rate for AFUDC was 3.6% in 2025, 4.8% in 2024 and 3.9% in 2023.

Generally, our subsidiaries follow the practice of charging maintenance and repairs, including the cost of removal of minor items of property, to expense as incurred. When our subsidiaries retire regulated property, plant and equipment, original cost plus the cost of retirement, less salvage value, is charged to accumulated depreciation. However, when it becomes probable a regulated asset will be retired substantially in advance of its original expected useful life or is abandoned, the cost of the asset and the corresponding accumulated depreciation is recognized as a separate asset. If the asset is still in operation, the gross amounts are classified as "Non-Utility and Other " as described in Note 9, "Property, Plant and Equipment." If the asset is no longer operating but still subject to recovery, the net amount is classified in "Regulatory assets" on the Consolidated Balance Sheets. If we are able to recover a full return of and on investment, the carrying value of the asset is based on historical cost. If we are not able to recover a full return on investment, a loss on impairment is recognized to the extent the net book value of the asset exceeds the present value of future revenues discounted at the incremental borrowing rate.

External and internal costs associated with on-premises computer software developed for internal use are capitalized. Capitalization of such costs commences upon the completion of the preliminary stage of each project. Once the installed software is ready for its intended use, such capitalized costs are amortized on a straight-line basis generally over a period of five years. External and internal up-front implementation costs associated with cloud computing arrangements that are service contracts are deferred on the Consolidated Balance Sheets, with the associated internal-use software capitalized to plant if the we have a contractual right to take possession of the software at any time during the hosting period without significant penalty and it is feasible for us to either run the software on our own hardware or contract with another party unrelated to the vendor to host the software. Once the installed software is ready for its intended use, such deferred costs are amortized on a straight-line basis to "Operation and maintenance," over the minimum term of the contract plus contractually-provided renewal periods that are reasonably expected to be exercised.

H. Goodwill and Other Intangible Assets. Substantially all of our goodwill relates to the excess of cost over the fair value of the net assets acquired in the Columbia acquisition on November 1, 2000. We test our goodwill for impairment annually as of May 1, or more frequently if events and circumstances indicate that goodwill might be impaired. Fair value of our reporting units is determined using a combination of income and market approaches. See Note 10, "Goodwill," for additional information.

I. Accounts Receivable Transfer Programs. Certain of our subsidiaries have agreements with third parties to transfer certain accounts receivable without recourse. These transfers of accounts receivable are accounted for as secured borrowings. The entire gross receivables balance remains on the December 31, 2025 and 2024 Consolidated Balance Sheets. When amounts are securitized, the short-term debt is recorded in the amount of proceeds received from the transferees involved in the transactions. Refer to Note 7, "Short-Term Borrowings," for further information.

J. Gas Cost and Fuel Adjustment Clause. Our regulated subsidiaries defer most differences between gas and fuel purchase costs and the recovery of such costs in revenues and adjust future billings for such deferrals on a basis consistent with applicable state-approved tariff provisions. These deferred balances are recorded as "Regulatory assets" or "Regulatory liabilities," as appropriate, on the Consolidated Balance Sheets. Refer to Note 12, "Regulatory Matters," for additional information.

K. Gas Storage and Other Inventories. Both the LIFO inventory methodology and the weighted average cost methodology are used to value natural gas in storage, as approved by regulators for all of our regulated subsidiaries. Inventory valued using LIFO was $42.5 million and $43.8 million at December 31, 2025 and 2024, respectively. Based on the average cost of gas using the LIFO method, the estimated replacement cost of gas in storage was less than the stated LIFO cost by $7.6 million at December 31, 2025 and was less than the stated LIFO cost by $12.8 million at December 31, 2024. As all LIFO inventory costs are collected from customers through our rate-regulated subsidiaries, no inventory impairment has been recorded. Gas inventory valued using the weighted average cost methodology was $209.5 million at December 31, 2025 and $135.8 million at December 31, 2024.

Electric production fuel is valued using the weighted average cost inventory methodology, as approved by NIPSCO's regulator.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Materials and supplies are valued using the weighted average cost inventory methodology. Materials and supplies are charged to expense or capitalized to property, plant and equipment when issued.

L. Accounting for Exchange and Balancing Arrangements of Natural Gas. Our Columbia Operations and NIPSCO Operations segment enters into balancing and exchange arrangements of natural gas as part of its operations and off-system sales programs. We record a receivable or payable for any of our respective cumulative gas imbalances, as well as for any gas inventory borrowed or lent under an exchange agreement. Exchange gas is valued based on individual regulatory jurisdiction requirements (for example, historical spot rate, spot at the beginning of the month). These receivables and payables are recorded as “Exchange gas receivable” or “Exchange gas payable” on our Consolidated Balance Sheets, as appropriate.

M. Accounting for Risk Management Activities. We account for our derivatives and hedging activities in accordance with ASC 815. We recognize all derivatives as either assets or liabilities on the Consolidated Balance Sheets at fair value, unless such contracts are exempted as a normal purchase normal sale under the provisions of the standard. The accounting for changes in the fair value of a derivative depends on the intended use of the derivative and resulting designation.

We do not offset the fair value amounts recognized for any of our derivative instruments against the fair value amounts recognized for the right to reclaim cash collateral or obligation to return cash collateral for derivative instruments executed with the same counterparty under a master netting arrangement. See Note 13, "Risk Management Activities," for additional information.

N. Income Taxes and Investment Tax Credits. Under the asset and liability method, deferred income taxes are provided for the tax consequences of temporary differences by applying enacted statutory tax rates applicable to future years to differences between the financial statement carrying amount and the tax basis of existing assets and liabilities. Investment tax credits and production tax credits associated with regulated operations are deferred and amortized as a reduction to income tax expense over a 10 year period and 1 year period, respectively. Furthermore, the tax basis of the asset is reduced by 50% of the ITCs received, resulting in a net deferred tax asset.

To the extent certain deferred income taxes of the regulated companies are recoverable or payable through future rates, regulatory assets and liabilities have been established. Regulatory assets for income taxes are primarily attributable to property-related tax timing differences for which deferred taxes had not been provided in the past when regulators did not recognize such taxes as costs in the rate-making process. Regulatory liabilities for income taxes are primarily attributable to the regulated companies’ obligation to refund to ratepayers deferred income taxes provided at rates higher than the current Federal income tax rate. Such property-related amounts are credited to ratepayers using either the average rate assumption method or the reverse South Georgia method. Non property-related amounts are credited to ratepayers consistent with state utility commission direction.

Pursuant to the Internal Revenue Code and relevant state taxing authorities, we and our subsidiaries generally file consolidated income tax returns for federal and certain state jurisdictions. We and our subsidiaries are parties to a tax sharing agreement under which income taxes recorded by each party represent amounts that would be owed had the party been separately subject to tax. Effective January 1, 2024, NIPSCO Accounts Receivable Corporation is no longer included in the consolidated group and now files a separate income tax return.

O. Pension Remeasurement. We utilize a third-party actuary for the purpose of performing actuarial valuations of our defined benefit plans. Annually, as of December 31, we perform a remeasurement for our defined benefit plans. Quarterly, we monitor for significant events, and if a significant event is identified, we perform a qualitative and quantitative assessment to determine if the resulting remeasurement would materially impact the NiSource financial statements. If material, an interim remeasurement is performed. See Note 16, "Pension and Other Postemployment Benefits," for additional information.

P. Environmental Expenditures. We accrue for costs associated with environmental remediation obligations, including expenditures related to asset retirement obligations and cost of removal, when the incurrence of such costs is probable and the amounts can be reasonably estimated, regardless of when the expenditures are actually made. The estimated future expenditures are based on currently enacted laws and regulations, existing technology and estimated site-specific costs where assumptions may be made about the nature and extent of site contamination, the extent of cleanup efforts, costs of alternative cleanup methods and other variables. The liability is adjusted as further information is discovered or circumstances change. The accruals for estimated environmental expenditures are recorded on the Consolidated Balance Sheets in “Other accruals” for short-term portions of these liabilities and “Other noncurrent liabilities and deferred credits” for the respective long-term portions of these liabilities. Rate-regulated subsidiaries applying regulatory accounting establish regulatory assets on the Consolidated Balance Sheets to the extent that future recovery of environmental remediation costs is probable through the regulatory process. Refer to Note 11, "Asset Retirement Obligations," and Note 19, "Other Commitments and Contingencies," for further information.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Q. Excise Taxes. As an agent for some state and local governments, we invoice and collect certain excise taxes levied by state and local governments on customers and record these amounts as liabilities payable to the applicable taxing jurisdiction. Such balances are presented within "Other accruals" on the Consolidated Balance Sheets. These types of taxes collected from customers, comprised largely of sales taxes, are presented on a net basis affecting neither revenues nor cost of sales. We account for excise taxes for which we are liable by recording a liability for the expected tax with a corresponding charge to “Other taxes” expense on the Statements of Consolidated Income.

R. Accrued Insurance Liabilities. We accrue for insurance costs related to workers compensation, automobile, property, general and employment practices liabilities based on the most probable value of each claim. In general, claim values are determined by professional, licensed loss adjusters who consider the facts of the claim, anticipated indemnification and legal expenses, and respective state rules. Claims are reviewed by us at least quarterly and an adjustment is made to the accrual based on the most current information.

S. Noncontrolling Interest. We maintain a controlling financial interest in certain of our less than wholly owned subsidiaries. We consolidate these subsidiaries as either voting interest entities or VIEs and present the third-party investors' portion of our net income (loss), net assets and comprehensive income (loss) as noncontrolling interest. Noncontrolling interest is included as a component of equity on the Consolidated Balance Sheet.

In December 2023, the NIPSCO Minority Interest Transaction closed and a 19.9% equity interest in NIPSCO Holdings II, the sole owner of NIPSCO, was issued to an affiliate of Blackstone. NIPSCO Holdings II does not meet the criteria of a VIE and instead is consolidated under the voting interest model in accordance with ASC 810 as we maintain control through a majority interest in NIPSCO Holdings II.

In October 2025, the GenCo Minority Interest Transaction closed and a 19.9% equity interest in Generation Holdings II, the sole owner of GenCo, was issued to affiliates of Blackstone. Generation Holdings II meets the criteria of a VIE and is consolidated in accordance with ASC 810 as we control the decisions that are significant to the VIE's ongoing operations and economic results (i.e., we are the primary beneficiary).

Refer to Note 4, "Noncontrolling Interests," for further discussion on the NIPSCO Minority Interest Transaction and GenCo Minority Interest Transaction.

We fund a portion of our renewable generation assets through JVs with tax equity partners. We consolidate these JVs in accordance with ASC 810 as they are VIEs in which we hold a variable interest, and we control decisions that are significant to the JVs' ongoing operations and economic results (i.e., we are the primary beneficiary).

These JVs are subject to profit sharing arrangements in which the allocation of the JVs' cash distributions and tax benefits to members is based on factors other than members' relative ownership percentages. As such, we utilize the HLBV method to allocate proceeds to each partner at the balance sheet date based on the liquidation provisions of the related JV's operating agreement and adjust the amount of the VIE's net income attributable to us and the noncontrolling tax equity member during the period.

In each reporting period, the application of HLBV to our consolidated VIEs results in a difference between the amount of profit from the consolidated JVs and the amount included in regulated rates. As discussed above in "F. Basis of Accounting for Rate-Regulated Subsidiaries," we are subject to the accounting and reporting requirements of ASC 980. In accordance with these principles, we recognize a regulatory liability or asset for amounts representing the timing difference between the profit earned from the JVs and the amount included in regulated rates to recover our approved investments in consolidated JVs. The amounts recorded in income will ultimately reflect the amount allowed in regulated rates to recover our investments over the useful life of the projects. The offset to the regulatory liability or asset associated with our renewable investments included in regulated rates is recorded in "Depreciation expense" on the Statements of Consolidated Income.

2. Recent Accounting Pronouncements

Recently Issued Accounting Pronouncements

In September 2025, the FASB issued ASU 2025-06, Intangibles—Goodwill and Other—Internal-Use Software (Subtopic 350-40): Targeted Improvements to the Accounting for Internal-Use Software. This pronouncement updates the guidance on capitalization of internal-use software, including removing the development stages utilized for evaluation of when certain activities are capital eligible. The ASU instead provides that an entity is required to start capitalizing eligible software

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

development costs when (1) management has authorized and committed to funding the software project and (2) it is probable that the project will be completed and the software will be used to perform the function intended, which is referred to as the “probable-to-complete recognition threshold”. This probable-to-complete threshold includes an evaluation of whether there is significant uncertainty associated with the development activities of the software. The ASU is effective for fiscal years beginning after December 15, 2027. We are currently evaluating the impacts this amendment will have on our internal-use software capitalization policy.

In November 2024, the FASB issued ASU 2024-03, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40). This pronouncement requires disaggregated disclosure of income statement expenses for public business entities. The ASU requires disclosure in tabular format of disaggregation of relevant expense captions presented on the income statement by certain natural expense categories with certain related qualitative disclosures within the notes to the financial statements. The ASU does not change the expense captions an entity presents on the income statement. The ASU is effective for fiscal years beginning after December 15, 2026, and interim reporting periods within annual reporting periods beginning after December 15, 2027, as defined in ASU 2025-01, Income Statement—Reporting Comprehensive Income—Expense Disaggregation Disclosures (Subtopic 220-40). We are currently evaluating the impacts this amendment will have on our required disclosures.

Recently Adopted Accounting Pronouncements

In December 2023, the FASB issued ASU 2023-09, Income Taxes (Topic 740): Improvements to Income Tax Disclosures. This pronouncement enhances required income tax disclosures. The pronouncement requires disclosure of specific categories and reconciling items included in the rate reconciliation, disaggregation between federal, state and local income taxes paid, and disclosure of income taxes paid by jurisdictions over a certain threshold. Additionally, the pronouncement eliminates certain required disclosures related to unrecognized tax benefits. We have adopted this ASU on a retrospective basis in the income tax footnote 15, for the year ended December 31, 2025.

3. Revenue Recognition

Customer Revenues. Substantially all of our revenues are tariff-based. Under ASC 606, the recipients of our utility service meet the definition of a customer, while the operating company tariffs represent an agreement that meets the definition of a contract, which creates enforceable rights and obligations. Customers in certain of our jurisdictions participate in programs that allow for a fixed payment each month regardless of usage. Payments received that exceed the value of gas or electricity actually delivered are recorded as a liability and presented in "Customer deposits and credits" on the Consolidated Balance Sheets. Amounts in this account are reduced and revenue is recorded when customer usage exceeds payments received.

We have identified our performance obligations created under tariff-based sales as i) the commodity (natural gas or electricity, which includes generation and capacity) and ii) delivery. These commodities are sold and / or delivered to and generally consumed by customers simultaneously, leading to satisfaction of our performance obligations over time as gas or electricity is delivered to customers. Due to the at-will nature of utility customers, performance obligations are limited to the services requested and received to date. Once complete, we generally maintain no additional performance obligations.

Transaction prices for each performance obligation are generally prescribed by each operating company’s respective tariff. Rates include provisions to adjust billings for fluctuations in fuel and purchased power costs and cost of natural gas. Revenues are adjusted for differences between actual costs, subject to reconciliation, and the amounts billed in current rates. Under or over recovered revenues related to these cost recovery mechanisms are included in "Regulatory assets" or "Regulatory liabilities" on the Consolidated Balance Sheets and are recovered from or returned to customers through adjustments to tariff rates. As we provide and deliver service to customers, revenue is recognized based on the transaction price allocated to each performance obligation. Distribution revenues are generally considered daily or "at-will" contracts as customers may cancel their service at any time (subject to notification requirements), and revenue generally represents the amount we are entitled to bill customers.

In addition to tariff-based sales, our gas distribution in both our Columbia Operations and NIPSCO Operations segments enters into balancing and exchange arrangements of natural gas as part of our operations and off-system sales programs. Performance obligations for these types of sales include transportation and storage of natural gas and can be satisfied at a point in time or over a period of time, depending on the specific transaction. For those transactions that span a period of time, we record a receivable or payable for any cumulative gas imbalances, as well as for any gas inventory borrowed or lent under a gas distribution operations exchange agreement.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Revenue Disaggregation and Reconciliation. We disaggregate revenue from contracts with customers based upon reportable segment, as well as by customer class. As of January 1, 2024, we have changed our reportable segments from Gas Distribution Operations and Electric Operations to Columbia Operations and NIPSCO Operations. Our historical segment disclosures have been recast to be consistent with the current presentation. For additional information see Note 21, "Business Segment Information".

The Columbia Operations segment provides regulated natural gas service and transportation for residential, commercial and industrial customers in Ohio, Pennsylvania, Virginia, Kentucky, and Maryland. The NIPSCO Operations segment provides regulated gas and electric service in northern Indiana for residential, commercial and industrial customers.

Other Revenues. As permitted by accounting principles generally accepted in the United States, regulated utilities have the ability to earn certain types of revenue that are outside the scope of ASC 606. These revenues primarily represent revenue earned under alternative revenue programs. Alternative revenue programs represent regulator-approved mechanisms that allow for the adjustment of billings and revenue for certain approved programs. We maintain a variety of these programs, including demand side management initiatives that recover costs associated with the implementation of energy efficiency programs, as well as normalization programs that adjust revenues for the effects of weather or other external factors. Additionally, we maintain certain programs with future test periods that operate similarly to FERC formula rate programs and allow for recovery of costs incurred to replace aging infrastructure. When the criteria to recognize alternative revenue have been met, we establish a regulatory asset and present revenue from alternative revenue programs on the Statements of Consolidated Income as “Other revenues”. When amounts previously recognized under alternative revenue accounting guidance are billed, we reduce the regulatory asset and record a customer account receivable.

The tables below reconcile revenue disaggregation by customer class to segment revenue, as well as to revenues reflected on the Statements of Consolidated Income:

Year Ended December 31, 2025 (in millions)			Columbia Operations						NIPSCO Operations						Corporate and Other						Total
Gas Distribution
Residential			$	2,279.9					$	708.0					$	—					$	2,987.9
Commercial			763.7						270.0						—						1,033.7
Industrial			167.4						100.2						—						267.6
Off-system			75.8						—						—						75.8
Wholesale			2.1						—						—						2.1
Miscellaneous(1)			35.9						13.5						—						49.4
Subtotal			$	3,324.8					$	1,091.7					$	—					$	4,416.5
Electric Generation and Power Delivery
Residential			$	—					$	768.4					$	—					$	768.4
Commercial			—						713.9						—						713.9
Industrial			—						578.3						—						578.3
Wholesale			—						45.1						—						45.1
Public Authority			—						9.5						—						9.5
Miscellaneous(1)			—						(8.9)						—						(8.9)
Subtotal			$	—					$	2,106.3					$	—					$	2,106.3
Total Customer Revenues**(2)**			3,324.8						3,198.0						—						6,522.8
Other Revenues**(3)**			5.2						109.3						4.9						119.4
Total Operating Revenues			$	3,330.0					$	3,307.3					$	4.9					$	6,642.2

(1)Amounts included in Columbia Operations are primarily related to earnings sharing mechanisms and late fees. Amounts included in NIPSCO Operations are primarily related to revenue refunds, public repairs and property rentals.

(2)Customer revenue amounts exclude intersegment revenues. See Note 21, "Business Segment Information," for discussion of intersegment revenues.

(3)Amounts included in Columbia Operations primarily relate to alternate revenue programs, including weather normalization adjustment mechanisms. Amounts included in NIPSCO Operations primarily relate to weather normalization adjustment mechanisms, MISO multi-value projects and revenue from non-jurisdictional transmission assets. Amounts included in Corporate and Other primarily relate to products and services revenue.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Year Ended December 31, 2024 (in millions)			Columbia Operations						NIPSCO Operations						Corporate and Other						Total
Gas Distribution
Residential			$	1,833.8					$	531.4					$	—					$	2,365.2
Commercial			580.3						199.2						—						779.5
Industrial			144.2						79.0						—						223.2
Off-system			42.6						—						—						42.6
Wholesale			1.2						—						—						1.2
Miscellaneous(1)			26.3						15.4						—						41.7
Subtotal			$	2,628.4					$	825.0					$	—					$	3,453.4
Electric Generation and Power Delivery
Residential			—						649.9						—						649.9
Commercial			—						620.4						—						620.4
Industrial			—						499.1						—						499.1
Wholesale			—						38.3						—						38.3
Public Authority			—						8.1						—						8.1
Miscellaneous(1)			—						13.7						—						13.7
Subtotal			$	—					$	1,829.5					$	—					$	1,829.5
Total Customer Revenues**(2)**			$	2,628.4					$	2,654.5					$	—					$	5,282.9
Other Revenues**(3)**			74.8						96.5						0.9						172.2
Total Operating Revenues			$	2,703.2					$	2,751.0					$	0.9					$	5,455.1

(1)Amounts included in Columbia Operations are primarily related to earnings sharing mechanisms and late fees. Amounts included in NIPSCO Operations are primarily related to revenue refunds, public repairs and property rentals.

(2)Customer revenue amounts exclude intersegment revenues. See Note 21, "Business Segment Information," for discussion of intersegment revenues.

(3)Amounts included in Columbia Operations primarily related to weather normalization adjustment mechanisms. Amounts included in NIPSCO Operations primarily relate to weather normalization adjustment mechanisms, MISO multi-value projects and revenue from non-jurisdictional transmission assets.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Year Ended December 31, 2023 (in millions)			Columbia Operations						NIPSCO Operations						Corporate and Other						Total
Gas Distribution
Residential			$	1,827.5					$	635.0					$	—					$	2,462.5
Commercial			598.9						249.0						—						847.9
Industrial			139.0						87.0						—						226.0
Off-system			60.6						—						—						60.6
Wholesale			1.6						—						—						1.6
Miscellaneous(1)			33.4						14.8						—						48.2
Subtotal			$	2,661.0					$	985.8					$	—					$	3,646.8
Electric Generation and Power Delivery
Residential			$	—					$	583.9					$	—					$	583.9
Commercial			—						578.1						—						578.1
Industrial			—						474.1						—						474.1
Wholesale			—						32.0						—						32.0
Public Authority			—						11.5						—						11.5
Miscellaneous(1)			—						21.4						—						21.4
Subtotal			$	—					$	1,701.0					$	—					$	1,701.0
Total Customer Revenues**(2)**			$	2,661.0					$	2,686.8					$	—					$	5,347.8
Other Revenues**(3)**			72.9						83.9						0.8						157.6
Total Operating Revenues			$	2,733.9					$	2,770.7					$	0.8					$	5,505.4

(1)Amounts included in Columbia Operations are primarily related to earnings share mechanisms and late fees. Amounts included in NIPSCO Operations are primarily related to late fees, property rentals, revenue refunds and adjustments.

(2)Customer revenue amounts exclude intersegment revenues. See Note 21, "Business Segment Information," for discussion of intersegment revenues.

(3)Amounts included in Columbia Operations primarily related to weather normalization adjustment mechanisms. Amounts included in NIPSCO Operations primarily related to MISO multi-value projects and revenue from non-jurisdictional transmission assets.

Customer Accounts Receivable. Accounts receivable on our Consolidated Balance Sheets includes both billed and unbilled amounts, as well as certain amounts that are not related to customer revenues. Unbilled amounts of accounts receivable relate to a portion of a customer’s consumption of gas or electricity from the date of their last cycle billing through the last day of the month (balance sheet date). Factors taken into consideration when estimating unbilled revenue include historical usage, customer rates, and weather. A significant portion of our operations are subject to seasonal fluctuations in sales. During the heating season, primarily from November through March, revenues and receivables from gas sales are more significant than in other months. The opening and closing balances of customer receivables for the year ended December 31, 2025, are presented in the table below. We had no significant contract assets or liabilities during the period. Additionally, we have not incurred any significant costs to obtain or fulfill contracts.

(in millions)			Customer Accounts Receivable, Billed (less reserve)						Customer Accounts Receivable, Unbilled (less reserve)
Balance as of December 31, 2024			$	525.1					$	408.1
Balance as of December 31, 2025			698.8						465.2

Utility revenues are billed to customers monthly on a cycle basis. We expect that substantially all customer accounts receivable will be collected following customer billing, as this revenue consists primarily of periodic, tariff-based billings for service and usage. We maintain common utility credit risk mitigation practices, including requiring deposits and actively pursuing collection of past due amounts. Our regulated operations also utilize certain regulatory mechanisms that facilitate recovery of bad debt costs within tariff-based rates, which provides further evidence of collectability. It is probable that substantially all of the consideration to which we are entitled from customers will be collected upon satisfaction of performance obligations.

Allowance for Credit Losses. To evaluate for expected credit losses, customer account receivables are pooled based on similar risk characteristics, such as customer type, geography, payment terms, and related macro-economic risks. Expected credit losses are established using a model that considers historical collections experience, current information, and reasonable and

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

supportable forecasts. Internal and external inputs are used in our credit model including, but not limited to, revenue projections, actual charge-offs data, recoveries data, shut-offs, security deposits and final bill data. We continuously evaluate available information relevant to assessing collectability of current and future receivables. We evaluate creditworthiness of specific customers periodically or following changes in facts and circumstances. When we become aware of a specific commercial or industrial customer's inability to pay, an allowance for expected credit losses is recorded for the relevant amount. We also monitor other circumstances that could affect our overall expected credit losses including, but not limited to, creditworthiness of overall population in service territories, adverse conditions impacting an industry sector, and current economic conditions. Bad debt expense for the year ended December 31, 2025 was $16.5 million higher than the prior year primarily due to increases in aged receivables and anticipated higher delinquencies following colder weather in the fourth quarter.

At each reporting period, we record expected credit losses to an allowance for credit losses account. When deemed to be uncollectible, customer accounts are written-off. A rollforward of our allowance for credit losses as of December 31, 2025 and December 31, 2024, are presented in the tables below:

(in millions)			Columbia Operations						NIPSCO Operations						Corporate and Other						Total
Balance as of December 31, 2024			$	9.8					$	13.9					$	—					$	23.7
Current period provisions			42.3						25.0						—						67.3
Write-offs charged against allowance			(50.8)						(15.0)						—						(65.8)
Recoveries of amounts previously written off			14.3						1.1						—						15.4
Balance as of December 31, 2025			$	15.6					$	25.0					$	—					$	40.6

(in millions)			Columbia Operations						NIPSCO Operations						Corporate and Other						Total
Balance as of December 31, 2023			$	10.2					$	11.9					$	0.8					$	22.9
Current period provisions			26.7						12.1						—						38.8
Write-offs charged against allowance			(43.9)						(11.0)						(0.8)						(55.7)
Recoveries of amounts previously written off			16.8						0.9						—						17.7
Balance as of December 31, 2024			$	9.8					$	13.9					$	—					$	23.7

4. Noncontrolling Interests

Variable Interest Entities.

A VIE is an entity in which the controlling interest is determined through means other than a majority voting interest. Refer to Note 1, "Nature of Operations and Summary of Significant Accounting Policies - S. Noncontrolling Interest," for information on our accounting policy for the VIEs.

NIPSCO is the managing member and operator of two wind JVs, Rosewater and Indiana Crossroads Wind, which have 102 MW and 302 MW of nameplate capacity, respectively. NIPSCO is also a managing member and operator of two solar JVs, Indiana Crossroads Solar and Dunns Bridge I, which have a nameplate capacity of 200 MW and 265 MW, respectively. We have determined that these JVs are VIEs. NIPSCO controls decisions that are significant to these entities' ongoing operations and economic results. Therefore, we have concluded that NIPSCO is the primary beneficiary and have consolidated all four entities.

Members of each respective JV include NIPSCO (who is the managing member) and a tax equity partner. Earnings, tax attributes and cash flows are allocated to both NIPSCO and the tax equity partner in varying percentages by category and over the life of the partnership. NIPSCO and each tax equity partner contributed cash to the respective JV. Once the tax equity partner has earned their negotiated rate of return and the JV has reached a stated contractual date, NIPSCO has the option to purchase the remaining interest in the respective JV from the tax equity partner. NIPSCO has an obligation to purchase 100% of the electricity generated by each commercially operational JV.

We did not provide any financial or other support for the JVs during the year that was not contractually required.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Our Consolidated Balance Sheets included the following assets and liabilities associated with the JV VIEs.

(in millions)			December 31, 2025						December 31, 2024
Net Property, Plant and Equipment			$	1,273.0					$	1,323.8
Current assets			27.6						65.0
Total assets(1)(2)			1,300.6						1,388.8
Current liabilities			16.1						53.7
Asset retirement obligations			55.7						58.3
Finance lease obligations			40.1						40.4
Total liabilities(1)(2)			$	111.9					$	152.4

(1)The assets of each VIE represent assets of a consolidated VIE that can be used only to settle obligations of the respective consolidated VIE. The creditors of the liabilities of the VIEs do not have recourse to the general credit of the primary beneficiary.

(2)In addition to the amounts disclosed above there is a de minimis amount of other noncurrent assets and liabilities at Rosewater as of December 31, 2025.

GenCo Minority Interest Transaction. In October 2025, NiSource issued a 19.9% equity interest in Generation Holdings II, the sole owner of GenCo, to BIP Orion Holdco L.P. and BIP Orion Holdco II L.P., affiliates of Blackstone (collectively, “Blackstone Investor”), in exchange for $35.2 million in cash contributions to Generation Holdings II through the Generation Holdings II LLC Agreement. Generation Holdings II is the sole owner of GenCo. Generation Holding II is considered a VIE as it passes the variability of its operating results through to its shareholders (Generation Holdings I and Blackstone Investor) and has insufficient equity to finance its activities without additional subordinated financial support. The sole purpose of the VIE is to own and operate GenCo which will acquire and build generation assets and provide capacity and electricity to support data center customers. Generation Holdings II and its wholly owned subsidiary, GenCo, is a consolidated VIE, as we have the power to direct the significant decision-making activities that most impact the ongoing operations and economic performance of the entity (i.e., we are the primary beneficiary) including business development and operating decisions.

The Generation Holdings II LLC Agreement establishes, among other things, governance rights, exit rights, requirements for additional capital contributions, mechanics for distributions, and other arrangements for Generation Holdings II. Specifically, under the terms of the Generation Holdings II LLC Agreement, Blackstone Investor will provide up to $1.325 billion in additional capital contributions over a seven-year period, which obligation is backed by an Equity Commitment Letter from Blackstone or an affiliate thereof. Under the Generation Holdings II LLC Agreement, Blackstone Investor is entitled to appoint two directors to the board of directors of Generation Holdings II (the “Board”) so long as Blackstone Investor (together with any approved affiliate) holds at least a 17.5% Percentage Interest (as defined in the Generation Holdings II LLC Agreement). The Board is comprised of seven directors, two appointed by Blackstone Investor and five appointed by NiSource. The Generation Holdings II LLC Agreement also contains certain investor protections, including, among other things, requiring Blackstone Investor approval for Generation Holdings II to take certain major actions outside of the normal course of business. In addition, the Generation Holdings II LLC Agreement contains certain terms surrounding transfer rights and other obligations applicable to both Blackstone Investor and NiSource. Under the Generation Holdings II LLC Agreement, Generation Holdings II has agreed that, so long as Blackstone Investor holds a 14.9% or greater percentage interest in Generation Holdings II, Generation Holdings II and/or its subsidiaries and NIPSCO Holdings II and/or its subsidiaries shall be the exclusive vehicles for all power, storage and generation requirements for data center customers within NIPSCO’s service territory. The Generation Holdings II LLC Agreement also establishes that NiSource will be attributed 80.1% of any profit or loss from Generation Holdings II, through its wholly owned subsidiary GenCo, with the Blackstone Investor being attributed the remaining 19.9% of any profit or loss.

For the twelve months ended December 31, 2025, Generation Holdings I contributed $344.9 million in cash and assets and the Blackstone Investor contributed $76.9 million in cash to Generation Holdings II. For the twelve months ended December 31, 2025, Generation Holdings I received a distribution of $35.2 million from Generation Holdings II.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Our Consolidated Balance Sheets included the following assets and liabilities associated with GenCo:

(in millions)			December 31, 2025
Net Property, Plant and Equipment			$	39.7
Current assets			62.5
Other assets			305.4
Total assets(1)			407.6
Current liabilities			40.8
Total liabilities(1)			$	40.8

(1)The assets of each VIE represent assets of a consolidated VIE that can be used only to settle obligations of the respective consolidated VIE. The creditors of the liabilities of the VIEs do not have recourse to the general credit of the primary beneficiary.

Voting Interest Entities

NIPSCO Minority Interest Transaction. In December 2023, we consummated the NIPSCO Minority Interest Transaction for a capital contribution of $2.16 billion in cash. The difference between the $2.16 billion consideration received and the $1.36 billion carrying value of the noncontrolling interest claim on net assets was recorded to additional paid-in capital, net of $54.7 million in transaction costs and a $63.5 million income tax benefit. We retain a controlling financial interest in NIPSCO Holdings II and its subsidiaries and consolidate their financial results. For the twelve months ending December 31, 2025, we received $154.4 million of contributions and made $74.6 million of distributions to our NIPSCO minority interest holders. For the twelve months ending December 31, 2024 we received $99.5 million of contributions and made $50.3 million of distributions to our NIPSCO minority interest holders. See Note 19, "Other Commitments and Contingencies - E. Other Matters," for a detailed discussion of the NIPSCO Holdings II LLC Agreement and governance structure.

In October 2025, the members of NIPSCO Holdings II entered into the Amended LLC Agreement, which, among other changes, increased the amount and time period for additional mandatory capital contributions required to be contributed by Blackstone Investor by $175 million and seven years, which obligation is backed by an Equity Commitment Letter from Blackstone or an affiliate thereof, and amended certain provisions to facilitate NIPSCO Holdings II and its subsidiaries’ provision of electric service to data center customers (and related activities) and their related contracts and arrangements with Generation Holdings II and its subsidiaries.

5. Earnings Per Share

The calculations of basic and diluted EPS are based on the weighted average number of shares of common stock and potential common stock outstanding during the period. Diluted EPS includes the incremental effects of the various long-term incentive compensation plans and ATM forward sale agreements under the treasury stock method when the impact would be dilutive. For the purposes of determining diluted EPS, for the twelve months ended December 31, 2023, the shares underlying the purchase contracts included within the Equity Units were included in the calculation of potential common stock outstanding using the if-converted method under US GAAP and we assumed share settlement of the remaining purchase contract payment balance from our Equity Units based on the average share price during the period. This method assumes conversion at the beginning of the reporting period, or at time of issuance, if later. The purchase contracts were settled on December 1, 2023. For the purchase contracts, the number of shares of our common stock that would have been issuable at the end of each reporting period prior to the settlement date were reflected in the denominator of our diluted EPS calculation. A numerator adjustment was reflected in the calculation of diluted EPS for interest expense incurred in 2023, net of tax, related to the purchase contracts.

The shares underlying the Series C Mandatory Convertible Preferred Stock included within the Equity Units were contingently convertible as the conversion was contingent on a successful remarketing. Contingently convertible shares where conversion was not tied to a market price trigger were excluded from the calculation of diluted EPS until such time as the contingency had been resolved under the if-converted method. The unsuccessful remarketing resolved the contingency and no shares were reflected in the denominator for the years ended December 31, 2023, for the calculation of diluted EPS.

We began using the two-class method of computing earnings per share in 2023 because we have participating securities in the form of non-vested restricted stock units with a non-forfeitable right to dividend equivalents, for which vesting is predicated solely on the passage of time. The calculation of earnings per share using the two-class method excludes income attributable to these participating securities from the numerator and excludes the dilutive impact of those shares from the denominator.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Basic net income per share is computed by dividing net income available to common shareholders by the weighted-average number of shares of common stock outstanding during the period. Diluted net income per share is computed by giving effect to all potential shares of common stock, to the extent they are dilutive. Refer to Note 6, "Equity," for additional information.

The following table presents the calculation of our basic and diluted EPS:

Year Ended December 31, (in millions, except per share amounts)			2025						2024						2023
Numerator:
Net Income Available to Common Shareholders			$	929.5					$	739.7					$	661.7
Less: Income allocated to participating securities			2.6						1.6						0.6
Net Income Available to Common Shareholders - Basic			$	926.9					$	738.1					$	661.1
Add: Dilutive effect of Equity Units			—						—						1.4
Net Income Available to Common Shareholders - Diluted			$	926.9					$	738.1					$	662.5
Denominator:
Average common shares outstanding - Basic			472.9						454.2						416.1
Dilutive potential common shares:
Equity Units purchase contracts			—						—						29.8
Equity Units purchase contract payment balance			—						—						0.9
Shares contingently issuable under employee stock plans			1.2						0.9						0.7
Shares restricted under employee stock plans			0.3						0.3						0.4
ATM Forward sale agreements			0.1						0.6						—
Average Common Shares - Diluted			474.5						456.0						447.9
Earnings per common share:
Basic			$	1.96					$	1.63					$	1.59
Diluted			$	1.95					$	1.62					$	1.48

6. Equity

Holders of shares of our common stock are entitled to receive dividends when, as, and if declared by the Board out of funds legally available. The policy of the Board has been to declare cash dividends on a quarterly basis payable on or about the 20th day of February, May, August and November. We have certain debt covenants that could restrict our ability to pay dividends or potentially limit the amount of dividends we could pay in order to maintain compliance with these covenants. Refer to Note 8, "Long-Term Debt," for more information. As of December 31, 2025, these covenants did not restrict our ability to pay dividends or the amount of dividends that were available to be paid.

There is no preferred stock outstanding as of December 31, 2025.

Common and preferred stock activity for 2025, 2024 and 2023 is described further below.

Details of our 2024 ATM program are summarized below:

• In February 2024, we entered into eight separate equity distribution agreements providing for the sale of up to an aggregate of $900.0 million of our common stock.

• During 2024, we executed and settled four forward sale agreements. Under these agreements, we issued 21,143,900 shares resulting in net proceeds of $600.3 million.

• In February 2025, we executed a forward sale agreement, which allowed us to issue a fixed number of shares at a price to be settled in the future. The forward purchaser under our forward sale agreement borrowed 2,000,000 shares from third parties, which the forward purchaser sold, through its affiliated agent, at a weighted average price of $40.10 per share. In September 2025, we settled the forward sale agreement in shares for $80.0 million, based on a net price of $40.02 per share.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

• In March 2025, we executed a forward sale agreement, which allowed us to issue a fixed number of shares at a price to be settled in the future. The forward purchaser under our forward sale agreement borrowed 1,707,320 shares from third parties, which the forward purchaser sold, through its affiliated agent, at a weighted average price of $41.00 per share. In September 2025, we settled the forward sale agreement in shares for $69.9 million, based on a net price of $40.92 per share.

• In June 2025, we executed a forward sale agreement, which allowed us to issue a fixed number of shares at a price to be settled in the future. The forward purchaser under our forward sale agreement borrowed 2,518,393 shares from third parties, which the forward purchaser sold, through its affiliated agent, at a weighted average price of $39.71 per share. In September 2025, we settled the forward sale agreement in shares for $99.1 million, based on a net price of $39.36 per share.

• In October 2025, with the commencement of our 2025 ATM program discussed below, we terminated the equity distribution agreements entered into in February 2024 in connection with the 2024 ATM program.

Details of our 2025 ATM program are summarized below:

• In October 2025, we entered into eleven separate equity distribution agreements providing for the sale of up to an aggregate of $1.5 billion of our common stock.

• In October 2025, we executed a direct sale agreement of 1,195,029 shares at a price of $41.84 resulting in net proceeds of $49.6 million received in November 2025.

• In October 2025, we executed a forward sale agreement, which allows us to issue a fixed number of shares at a price to be settled in the future. The forward purchaser under our forward sale agreement borrowed 2,390,057 shares from third parties, which the forward purchaser sold, through its affiliated agent, at a weighted average price of $41.84 per share. We may settle the forward sale agreement in shares, cash or net shares by October 2026. Had we settled all the shares under the forward sale agreement at December 31, 2025, we would have received approximately $99.7 million, based on a net price of $41.73 per share.

• As of December 31, 2025, the 2025 ATM program inclusive of the forward sale agreement had approximately $1.35 billion of equity capacity available. The 2025 ATM program expires in December 2028.

Series A Preferred Stock. During 2023, there were $28.25 dividends declared per share for the Series A Preferred Stock. There were no dividends declared per share for the Series A Preferred Stock during 2024 and 2025.

In June 2023, we redeemed all 400,000 outstanding shares of Series A Preferred Stock for a redemption price of $1,000 per share or $400.0 million in total.

Series B and B-1 Preferred Stock. During 2024 and 2023, dividends declared per share for the Series B Preferred Stock were $406.25 and $1,625.0, respectively. There were no dividends declared per share for the Series B Preferred Stock during 2025.

In March 2024, we redeemed all 20,000 outstanding shares of Series B Preferred Stock for a redemption price of $25,000 per share and all 20,000 outstanding shares of Series B-1 Preferred Stock for a redemption price of $0.01 per share or $500.0 million in total. Following the redemption, dividends ceased to accrue on the shares of Series B Preferred Stock, shares of the Series B Preferred Stock and Series B-1 Preferred Stock were no longer deemed outstanding and all rights of the holders of such shares of Series B Preferred Stock and Series B-1 Preferred Stock terminated. In conjunction with the redemption, we recorded a $14.0 million preferred stock redemption premium, calculated as the difference between the carrying value on the redemption date of the Series B Preferred Stock and Series B-1 Preferred Stock and the total amount of consideration paid to redeem, which was recorded as a reduction to retained earnings during the first quarter of 2024. We did not recognize an excise tax liability under the IRA in connection with this redemption as we issued common stock in 2024 in excess of the fair value of the Series B Preferred Stock and Series B-1 Preferred Stock redeemed.

In March 2024, we filed a Certificate of Elimination to our Amended and Restated Certificate of Incorporation with the Secretary of State of Delaware to eliminate from the Amended and Restated Certificate of Incorporation all matters set forth in the Certificate of Designations with respect to the Series B Preferred Stock and the Certificate of Designations with respect to

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

the Series B-1 Preferred Stock. As a result, the 20,000 shares that were previously designated as Series B Preferred Stock and the 20,000 shares that were previously designated as Series B-1 Preferred Stock were returned to the status of authorized but unissued shares of preferred stock, par value $0.01 per share, without designation as to series. The Certificate of Elimination does not change the total number of authorized shares of capital stock of NiSource or the total number of authorized shares of preferred stock. We voluntarily delisted the preferred stock from the New York Stock Exchange in March 2024.

Equity Units. In December 2023, we issued 33,898,837 shares of our common stock under the purchase contract component of the Corporate Units. As of December 2023, each holder of Corporate Units was deemed to have automatically delivered to us the related Series C Mandatory Convertible Preferred Stock that were components of the Corporate Units in full satisfaction of such holder’s obligations under the related purchase contract, and all 862,500 shares of Series C Mandatory Convertible Preferred Stock were returned to the status of authorized but unissued preferred stock, par value of $0.01 per share, without designation as to series. We voluntarily delisted the Corporate Units from the New York Stock Exchange in December 2023.

Refer to Note 5, "Earnings Per Share," for additional information regarding our treatment of the Equity Units for diluted EPS.

Noncontrolling Interest in Consolidated Subsidiaries. As of December 31, 2025 and 2024, NIPSCO and tax equity partners have completed their cash contributions into the Indiana Crossroads Wind, Rosewater, Indiana Crossroads Solar and Dunn's Bridge I JVs. Earnings, tax attributes and cash flows are allocated to both NIPSCO and the respective tax equity partners in varying percentages by category and over the life of the partnership. The tax equity partner's contributions, net of these allocations, is represented as a noncontrolling interest within total equity on the Consolidated Balance Sheets. Refer to Note 4, "Noncontrolling Interests," for more information.

In December 2023, we consummated the closing of the NIPSCO Minority Interest Transaction and issued a 19.9% equity interest in NIPSCO Holdings II LLC to BIP in exchange for a capital contribution of $2.16 billion in cash. Transaction costs and deferred tax impacts of $54.7 million and $63.5 million, respectively, were recorded during the period ending December 31, 2023. Refer to Note 4, "Noncontrolling Interests," Note 15, "Income Taxes," and Note 19, "Other Commitments and Contingencies - E. Other Matters," in the Notes to the Consolidated Financial Statements for more information on this transaction.

In October 2025, NiSource issued a 19.9% direct equity interest in NiSource’s wholly-owned subsidiary Generation Holdings II to BIP Orion Holdco L.P. and BIP Orion Holdco II L.P., affiliates of Blackstone (collectively, “Blackstone Investor”), in exchange for $35.2 million. In October 2025, simultaneously with issuance of the 19.9% equity interest in Generation Holdings II, Blackstone Investor, Generation Holdings I, Generation Holdings II and NiSource entered into Generation Holdings II LLC Agreement. Refer to Note 4, "Noncontrolling Interests," and Note 19, "Other Commitments and Contingencies - E. Other Matters," for more information.

7. Short-Term Borrowings

We generate short-term borrowings from our revolving credit facility, commercial paper program and accounts receivable transfer programs. Each of these borrowing sources is described further below.

Revolving Credit Facility. We maintain a revolving credit facility to fund ongoing working capital requirements, including the provision of liquidity support for our commercial paper program, the issuance of letters of credit and also for general corporate purposes. Our revolving credit facility has a facility limit of $2.50 billion and is comprised of a syndicate of banks. In December 2025, we extended the termination date of our revolving credit facility to December 2030 and increased our facility limit from $1.85 billion to $2.50 billion. At December 31, 2025 and 2024, we had no outstanding borrowings under this facility.

Commercial Paper Program. In February 2024, we increased our program limit from $1.50 billion to $1.85 billion. We had $736.0 million and $604.6 million of commercial paper outstanding with weighted-average interest rates of 3.92% and 4.73% as of December 31, 2025 and 2024, respectively.

Accounts Receivable Transfer Programs. Columbia of Ohio, NIPSCO, and Columbia of Pennsylvania each maintain a receivables agreement whereby they transfer their customer accounts receivables to third party financial institutions through consolidated special purpose entities. The three agreements expire between May 2026 and October 2026 and may be further extended if mutually agreed to by the parties thereto.

All receivables transferred to third parties are valued at face value, which approximates fair value due to their short-term nature. The amount of the undivided percentage ownership interest in the accounts receivables transferred is determined in part by required loss reserves under the agreements.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Transfers of accounts receivable are accounted for as secured borrowings resulting in the recognition of short-term borrowings on the Consolidated Balance Sheets. As of December 31, 2025, the maximum amount we could borrow related to our accounts receivable programs is $175.0 million.

We had no short-term borrowings related to the securitization transactions as of December 31, 2025 and 2024, respectively.

For the year ended December 31, 2025 and 2024, zero and $337.6 million, respectively, was recorded as cash flows used for financing activities related to the change in short-term borrowings due to securitization transactions. For the accounts receivable transfer programs, we pay used facility fees for amounts borrowed, unused commitment fees for amounts not borrowed and upfront renewal fees. Fees associated with the securitization transactions were $1.4 million, $1.5 million, and $2.7 million for the years ended December 31, 2025, 2024 and 2023, respectively. Columbia of Ohio, NIPSCO and Columbia of Pennsylvania remain responsible for collecting the receivables securitized, and the receivables cannot be transferred to another party. Refer to Note 23, "Interest Expense, Net," for additional information on securitization transaction fees.

Items listed above are presented net in the Statements of Consolidated Cash Flows as their maturities are less than 90 days.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

8. Long-Term Debt

Our long-term debt as of December 31, 2025 and 2024 is as follows:

Long-term debt type			Maturity as of December 31, 2025			Weighted average interest rate (%)						Outstanding balance as of December 31, (in millions)
			2025						2024
Senior notes:
NiSource			August 2025			0.950		%				$	—					$	1,250.0
NiSource			May 2027			3.490		%				1,000.0						1,000.0
NiSource			December 2027			6.780		%				3.0						3.0
NiSource			March 2028			5.250		%				1,050.0						1,050.0
NiSource			July 2029			5.200		%				600.0						600.0
NiSource			September 2029			2.950		%				750.0						750.0
NiSource			May 2030			3.600		%				1,000.0						1,000.0
NiSource			February 2031			1.700		%				750.0						750.0
NiSource			June 2033			5.400		%				450.0						450.0
NiSource			April 2034			5.350		%				650.0						650.0
NiSource			July 2035			5.350		%				900.0						—
NiSource			December 2040			6.250		%				152.6						152.6
NiSource			June 2041			5.950		%				347.4						347.4
NiSource			February 2042			5.800		%				250.0						250.0
NiSource			February 2043			5.250		%				500.0						500.0
NiSource			February 2044			4.800		%				750.0						750.0
NiSource			February 2045			5.650		%				500.0						500.0
NiSource			May 2047			4.375		%				1,000.0						1,000.0
NiSource			March 2048			3.950		%				750.0						750.0
NiSource			June 2052			5.000		%				350.0						350.0
NiSource			April 2055			5.850		%				1,500.0						—
Total senior notes												$	13,253.0					$	12,103.0
Junior subordinated notes:
NiSource			November 2054			6.950		%				$	500.0					$	500.0
NiSource			March 2055			6.375		%				500.0						500.0
NiSource			July 2056			5.750		%				1,000.0						—
Total junior subordinated notes												$	2,000.0					$	1,000.0
Medium term notes:
NiSource			May 2027			7.990		%				$	29.0					$	29.0
NIPSCO			June 2027 to August 2027			7.644		%				58.0						58.0
Columbia of Massachusetts			December 2025			6.430		%				—						10.0
Columbia of Massachusetts			February 2028			6.260		%				5.0						5.0
Total medium term notes												$	92.0					$	102.0
Finance leases:
NiSource Corporate Services			January 2026 to September 2027			4.350		%				$	5.0					$	14.6
NIPSCO			December 2027 to December 2063			5.480		%				165.5						124.3
Columbia of Ohio			December 2035 to March 2052			6.110		%				81.7						85.6
Columbia of Virginia			July 2029 to November 2039			5.620		%				16.2						15.2
Columbia of Kentucky			May 2027			5.360		%				0.1						0.1
Columbia of Pennsylvania			March 2030 to May 2035			4.430		%				5.5						6.4
Total finance leases												$	274.0					$	246.2
Less: Unamortized issuance costs and discounts												(141.5)						(95.5)
Less: Current portion of long term debt												(19.7)						(1,281.2)
Total Long-Term Debt												$	15,457.8					$	12,074.5

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Details of our 2025 long-term debt activity are summarized below:

• In March 2025, we completed the issuance and sale of $750.0 million of 5.850% senior unsecured notes maturing in 2055, which resulted in approximately $739.6 million of net proceeds after discount and debt issuance costs.

• In June 2025, we completed the issuance and sale of an additional $750.0 million of 5.850% senior unsecured notes maturing in 2055 (the "2055 Notes"). The terms of the 2055 Notes, other than the issue date and the price to the public, are identical to the terms of, and constitute a reopening of, our 5.850% senior unsecured notes maturing in 2055 issued in March, 2025. With the incremental issuance, we now have $1.5 billion of 5.850% senior unsecured notes maturing in 2055. In June 2025, we also completed the issuance and sale of $900.0 million of 5.350% senior unsecured notes maturing in 2035 (the "2035 Notes"). The issuances of the 2055 Notes and the 2035 Notes in June, 2025 resulted in approximately $1.616 billion of total net proceeds after discount and debt issuance costs.

• In August 2025, we repaid $1,250.0 million of 0.95% senior unsecured notes at maturity.

• In November 2025, we completed the issuance and sale of $1.0 billion of 5.750% fixed-to-fixed reset rate junior subordinated notes maturing in 2056, which resulted in approximately $984.3 million of net proceeds after debt issuance costs. The subordinated notes bear interest (i) from and including November 2025 to, but excluding, July 2031 at a rate of 5.75% per annum and (ii) from and including July 2031, during each five-year reset period at a rate per annum equal to the five-year U.S. treasury rate (determined as described in the prospectus supplement filed with the SEC in November 2025) as of the then most recent reset interest determination date plus a spread of 2.035%, to be reset on each reset date; provided that the interest rate during any reset period will not reset below 5.750% per annum. At our option, we may redeem some or all of the subordinated notes during specified periods, and upon the occurrence of certain ratings or tax events, all as described in the prospectus supplement. In accordance with terms of the subordinated notes, we have the right, from time to time, to defer the payment of interest on the outstanding subordinated notes on one or more occasions for up to ten consecutive years. In the event that we were to exercise such right to defer interest on the subordinated notes, we would not be able to pay cash dividends on the common stock during the periods in which such payments were deferred.

• In December 2025, Columbia of Massachusetts repaid $10.0 million of 6.430% medium term notes at maturity.

Details of our 2024 long-term debt activity are summarized below:

• In March 2024, we completed the issuance and sale of $650.0 million of 5.350% senior unsecured notes maturing in 2034, which resulted in approximately $642.6 million of net proceeds after discount and debt issuance costs.

• In May 2024, we completed the issuance and sale of $500.0 million of 6.950% fixed-to-fixed reset rate junior subordinated notes maturing in 2054, which resulted in approximately $493.4 million of net proceeds after debt issuance costs. The subordinated notes bear interest (i) from and including May 2024 to, but excluding, November 2029 at a rate of 6.950% per annum and (ii) from and including November 2029, during each five-year reset period at a rate per annum equal to the five-year U.S. treasury rate (determined as described in the prospectus supplement filed with the SEC in May 2024) as of the then most recent reset interest determination date plus a spread of 2.451%, to be reset on each reset date. At our option, we may redeem some or all of the subordinated notes during specified periods, and upon the occurrence of certain ratings or tax events, all as described in the prospectus supplement. In accordance with terms of the subordinated notes, we have the right, from time to time, to defer the payment of interest on the outstanding subordinated notes on one or more occasions for up to ten consecutive years. In the event that we were to exercise such right to defer interest on the subordinated notes, we would not be able to pay cash dividends on the common stock during the periods in which such payments were deferred.

• In June 2024, we completed the issuance and sale of $600.0 million of 5.200% senior unsecured notes maturing in 2029, which resulted in approximately $593.7 million of net proceeds after discount and debt issuance costs.

• In September 2024, we completed the issuance and sale of $500.0 million of 6.375% fixed-to-fixed reset rate junior subordinated notes maturing in 2055, which resulted in approximately $493.6 million of net proceeds after debt issuance costs. The subordinated notes bear interest (i) from and including September 2024 to, but excluding, March 2035 at a rate of 6.375% per annum and (ii) from and including March 2035, during each five-year reset period at a rate per annum equal to the five-year U.S. treasury rate (determined as described in the prospectus supplement filed with the SEC in September 2024) as of the then most recent reset interest determination date plus a spread of 2.527%,

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

to be reset on each reset date. At our option, we may redeem some or all of the subordinated notes during specified periods, and upon the occurrence of certain ratings or tax events, all as described in the prospectus supplement. In accordance with terms of the subordinated notes, we have the right, from time to time, to defer the payment of interest on the outstanding subordinated notes on one or more occasions for up to ten consecutive years. In the event that we were to exercise such right to defer interest on the subordinated notes, we would not be able to pay cash dividends on the common stock during the periods in which such payments were deferred.

See Note 19, "Other Commitments and Contingencies - A. Contractual Obligations," for the outstanding long-term debt maturities at December 31, 2025.

Unamortized debt expense, premium and discount on long-term debt applicable to outstanding bonds are being amortized over the life of such bonds.

We are subject to a financial covenant under our revolving credit facility which requires us to maintain a debt to capitalization ratio that does not exceed 70%. As of December 31, 2025, the ratio was 51.0%.

We are also subject to certain other non-financial covenants under the revolving credit facility. Such covenants include a limitation on the creation or existence of new liens on our assets, generally exempting liens on utility assets, purchase money security interests, preexisting security interests and an additional subset of assets equal to $500 million. An asset sale covenant generally restricts the sale, conveyance, lease, transfer or other disposition of our assets to those dispositions that are for a price not materially less than fair market of such assets, that would not materially impair our ability to perform obligations under the revolving credit facility, and that together with all other such dispositions, would not have a material adverse effect. The covenant also restricts dispositions to no more than 15% of our consolidated total assets as of the last day of our fiscal year then most recently ended for which financial statements have been delivered. Additionally, the revolving credit facility requires us to own directly or indirectly at least 70% of NIPSCO. The revolving credit facility also includes a cross-default provision, which triggers an event of default under the credit facility in the event of an uncured payment default relating to any indebtedness of us or any of our subsidiaries in a principal amount of $100.0 million or more.

Our indentures generally do not contain any financial maintenance covenants. However, our indentures are generally subject to cross-default provisions ranging from uncured payment defaults of $5.0 million to $50.0 million, and limitations on the incurrence of liens on our assets, generally exempting liens on utility assets, purchase money security interests, preexisting security interests and an additional subset of assets capped at 10% of our consolidated net tangible assets.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

9. Property, Plant and Equipment

Our property, plant and equipment on the Consolidated Balance Sheets are classified as follows:

At December 31, (in millions)			2025						2024
Property, Plant and Equipment
Gas distribution utility			$	21,509.4					$	20,007.2
Electric utility			11,420.7						8,666.8
Corporate			236.4						248.1
Construction work in process			1,700.7						2,084.7
JV renewable generation assets(1)			1,429.3						1,434.2
Non-utility and other			1,762.3						1,711.9
Total Property, Plant and Equipment			$	38,058.8					$	34,152.9
Accumulated Depreciation and Amortization
Gas distribution utility			$	(4,427.3)					$	(4,166.8)
Electric utility			(2,987.0)						(2,707.8)
Corporate			(156.1)						(163.4)
JV renewable generation assets(1)			(156.3)						(110.4)
Non-utility and other			(1,643.9)						(1,550.6)
Total Accumulated Depreciation and Amortization			$	(9,370.6)					$	(8,699.0)
Net Property, Plant and Equipment			$	28,688.2					$	25,453.9

(1)These JV renewable generation assets owned and operated by JVs between NIPSCO and unrelated tax equity partners represent Non-Utility Property, are depreciated straight-line over 30 years and are part of our NIPSCO Operations segment. Refer to Note 4, "Noncontrolling Interests," for additional information.

The weighted average depreciation provisions for utility plant, as a percentage of the original cost, for the periods ended December 31, 2025, 2024 and 2023 were as follows:

			2025						2024						2023
NIPSCO Operations			3.0		%				3.0		%				3.0		%
Columbia Operations			2.6		%				2.6		%				2.5		%

We recognized depreciation expense of $1,008.9 million, $820.4 million and $756.9 million for the years ended 2025, 2024 and 2023, respectively. The 2025, 2024 and 2023, depreciation expense includes $62.4 million, $58.9 million, and $12.5 million related to the regulatory deferral of income associated with our JVs. See Note 1, "Nature of Operations and Summary of Significant Accounting Policies - S. Noncontrolling Interest," for additional details.

Amortization of on-premises Software Costs. We amortized $76.0 million, $85.2 million and $77.5 million in 2025, 2024 and 2023, respectively, related to software recorded as intangible assets. Our unamortized software balance was $390.3 million and $236.1 million at December 31, 2025 and 2024, respectively.

Amortization of Cloud Computing Costs. We amortized $27.0 million, $17.7 million and $12.6 million in 2025, 2024 and 2023, respectively, related to cloud computing costs to "Operation and maintenance" expense. Our unamortized cloud computing balance was $165.1 million and $77.5 million at December 31, 2025 and 2024, respectively.

10. Goodwill

The following presents our goodwill balance allocated by segment as of December 31, 2025:

(in millions)						Columbia Operations						NIPSCO Operations												Total
Goodwill						$	1,468.1					$	17.8											$	1,485.9

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

For our annual goodwill impairment analysis performed as of May 1, 2025, we performed a qualitative "step 0" assessment and determined that it was more likely than not that the estimated fair value of a reporting unit substantially exceeded its carrying value of our reporting unit. For this test, we assessed various assumptions, events and circumstances that would have affected the estimated fair value of the reporting unit as compared to its baseline May 1, 2024 "step 1" fair value measurement. There have been no impairments recorded during the periods presented.

11. Asset Retirement Obligations

We have recognized asset retirement obligations associated with various legal obligations including costs to remove and dispose of certain construction materials located within many of our facilities (including our JV facilities), certain costs to retire pipeline, removal costs for certain underground storage tanks, closure costs for certain sites including ash ponds, solid waste management units and a landfill, as well as some other nominal asset retirement obligations. We also have an obligation associated with the decommissioning of our two hydro facilities located in Indiana. These hydro facilities have an indeterminate life, and as such, no asset retirement obligation has been recorded.

During 2025, we continued to evaluate the applicability of revisions to the EPA rule for disposal of CCRs, which was announced in May 2024. As a result, during 2025, we recorded an increase of $48.9 million based on initial assessments of estimated costs to comply with the EPA rule for certain sites. Additional costs will be recorded if they become probable and estimable. These costs are expected to be recoverable through existing and future depreciation rates. See Note 19, "Other Commitments and Contingencies - D. Environmental Matters," for additional information on the legacy CCR rule.

Changes in our liability for asset retirement obligations for the years 2025 and 2024 are presented in the table below:

(in millions)			2025						2024
Beginning Balance			$	783.2					$	553.0
Accretion recorded as a regulatory asset/liability			38.0						25.3
Additions			63.3						189.9
Settlements			(73.0)						(72.5)
Change in estimated cash flows			25.4						87.5
Ending Balance			$	836.9					$	783.2

Certain non-legal costs of removal not yet incurred but have been, and continue to be, included in depreciation rates and collected in the customer rates of the rate-regulated subsidiaries are classified as "Regulatory liabilities" on the Consolidated Balance Sheets.

12. Regulatory Matters

Regulatory Filings

Renewable generation filings. In February 2025, NIPSCO filed a petition with the IURC to modify its February 2023 order that approved a power purchase agreement related to Templeton and allow for NIPSCO to fully own Templeton. The IURC issued an order in September 2025 approving the filed petition.

NIPSCO Electric rate case filing. In February 2025, NIPSCO and certain intervening parties filed a Joint Stipulation and Settlement Agreement with the IURC. The IURC issued an order in June 2025, approving the Settlement Agreement without modification. New rates were implemented in multiple steps beginning in July 2025 and will continue with the final step no later than March 2026.

Columbia of Pennsylvania rate case filing. In December 2025, the Pennsylvania Public Utility Commission issued a final order accepting in part, and denying in part, Columbia's exceptions to the recommended decision issued by the Administrative Law Judges. The final order approved the continuation of a pilot residential Weather Normalization Adjustment with a few modifications (most notably increasing the percentage range in which weather normalization is applied from 3% to 5% and an increase to the residential fixed customer charge to $20.15. Rates became effective in January 2026. Two parties have filed petitions for reconsideration on certain aspects of the final order and petitions for reconsideration are pending.

GenCo filing. In January 2025, GenCo, an indirect subsidiary of NiSource Inc., filed a declination of jurisdiction petition with the IURC related to the ownership, development, financing, construction and operation of generation facilities. This was an

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

administrative filing and is a step in NIPSCO’s effort to set up a framework to accommodate megaload customers, including data centers. A settlement agreement among GenCo, NIPSCO, and a coalition of NIPSCO's largest industrial customers was approved by the IURC in September 2025. In October 2025, the Indiana Office of the Utility Consumer Counselor ("OUCC") filed a limited Request for Rehearing with the IURC and the OUCC filed a Notice of Appeal of the IURC order approving the GenCo settlement, which was immediately stayed by the Court of Appeals to allow the IURC process to be completed. In November 2025, the IURC issued an order granting the OUCC’s limited request for rehearing, which was supported by NIPSCO and GenCo. In December 2025, all parties who originally appealed the IURC approval filed motions to dismiss their respective appeals.

NIPSCO Electric Special Contract and GenCo PPA filing. In November 2025, NIPSCO and GenCo filed an application with the IURC seeking approval of (i) a retail special contract for electric service between NIPSCO and ADS, (ii) a related power purchase agreement between NIPSCO and GenCo, and (iii) an alternative regulatory plan and associated accounting treatment. Testimony from the OUCC and intervenors was filed in January 2026. The OUCC and one other intervenor were generally supportive of approval of the special contract and GenCo PPA, while one intervenor sought certain modifications to the special contract. A hearing is scheduled for February 2026. An order is anticipated in the second quarter of 2026.

202(c) Emergency Order for R.M. Schahfer coal facility. In December 2025, before the planned retirement of the R.M. Schahfer coal facility, the U.S. Secretary of Energy issued an emergency order under section 202(c) of the Federal Power Act requiring R.M. Schahfer to continue operating for 90 days, through March 23, 2026. The order stated that continued operation of R.M. Schahfer was required to meet an energy emergency across MISO’s North and Central regions. Following receipt of the emergency order, NIPSCO filed a complaint at FERC seeking a modification of the MISO Tariff to establish a mechanism for recovery and allocation of the cost to comply with this order. NIPSCO made two filings with the IURC related to the emergency order. The first filing is to confirm accounting treatment of the current electric rate order, and the second is a filing for recovery of federally mandated expenses related to the emergency order, which will be utilized in the event that any costs of complying with the emergency order fall outside of the MISO Tariff recovery. The Michigan City coal facility is scheduled to be retired by the end of 2028.

IURC Investigation. In November 2025, the IURC initiated an investigation into the accuracy of NIPSCO’s gas meters. This investigation followed NIPSCO's disclosure of a latent issue with a small percentage of the meter indexes in NIPSCO's gas meters, which was discovered during roll-out of new AMI communications modules for gas meters. A procedural schedule has been established and a hearing is expected in July 2026.

Regulatory Assets and Liabilities. We follow the accounting and reporting requirements of ASC Topic 980, which provides that regulated entities account for and report assets and liabilities consistent with the economic effect of regulatory rate-making procedures when the rates established are designed to recover the costs of providing the regulated service and it is probable that such rates will be charged and collected from customers. Certain expenses and credits subject to utility regulation or rate determination normally reflected in income or expense are deferred on the balance sheet and are recognized in the income statement as the related amounts are included in customer rates and recovered from or refunded to customers. We assess the probability of collection for all of our regulatory assets each period. The offset to the regulatory liability associated with our renewable investments included in regulated rates is recorded in "Depreciation and amortization" on the Statements of Consolidated Income.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Regulatory assets were comprised of the following items:

At December 31, (in millions)			2025						2024
Regulatory Assets
Unrecognized pension and other postretirement benefit costs (see Note 16)			$	433.1					$	485.3
Deferred pension and other postretirement benefit costs (see Note 16)			30.8						45.3
Environmental costs (see Note 19-D.)			42.0						42.8
Regulatory effects of accounting for income taxes (see Note 1-N. and Note 15)			190.8						172.0
Under-recovered gas and fuel costs (see Note 1-J.)			41.3						82.3
Depreciation			218.4						214.9
Post-in-service carrying charges			287.2						280.8
Safety activity costs			200.6						203.7
DSM programs			13.4						17.8
Retired coal generating stations			552.1						617.0
Losses on commodity price risk programs (See Note 13)			10.1						6.5
Deferred property taxes			79.4						75.9
Renewable energy investments			130.7						81.3
WAM system filing			33.5						21.5
Customer assistance programs			17.3						24.4
Uncollected future cost of removal			102.5						—
Other			116.2						105.8
Total Regulatory Assets			$	2,499.4					$	2,477.3
Less: Current Portion			274.2						319.9
Total Noncurrent Regulatory Assets			$	2,225.2					$	2,157.4

Regulatory liabilities were comprised of the following items:

At December 31, (in millions)			2025						2024
Regulatory Liabilities
Over-recovered gas and fuel costs (see Note 1-J.)			$	50.6					$	21.4
Cost of removal (see Note 11)			454.5						482.8
Regulatory effects of accounting for income taxes (see Note 1-N. and Note 15)			869.3						827.0
Deferred pension and other postretirement benefit costs (see Note 16)			28.0						40.4
Gains on commodity price risk programs (See Note 13)			19.2						28.7
Customer assistance programs			10.6						9.4
Off-system sales sharing			21.8						21.4
Renewable energy investments (See Note 1-S. and Note 4)			139.4						77.0
Rate refunds			68.9						16.6
Other			111.1						57.0
Total Regulatory Liabilities			$	1,773.4					$	1,581.7
Less: Current Portion			260.1						150.5
Total Noncurrent Regulatory Liabilities			$	1,513.3					$	1,431.2

Regulatory assets, including under-recovered gas and fuel costs and depreciation, of approximately $499.3 million and $671.3 million as of December 31, 2025 and 2024, respectively, are not earning a return on investment. These costs are recovered over a remaining life of between 15 and 75 years.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Assets:

Unrecognized pension and other postretirement benefit costs. Represents the deferred other comprehensive income or loss of the actuarial gains or losses and the prior service costs or credits that arise during the period but that are not immediately recognized as components of net periodic benefit costs by certain subsidiaries that will ultimately be recovered through base rates.

Deferred pension and other postretirement benefit costs. Primarily relates to the difference between defined benefit plan expense recorded by certain subsidiaries due to regulatory orders and the corresponding expense that would otherwise be recorded in accordance with GAAP. This balance is driven by Columbia of Ohio deferrals.

Environmental costs. Includes certain recoverable costs related to gas plant sites, disposal sites or other sites onto which material may have migrated. The recovery of these costs is to be addressed in future base rates, billing riders or tracking mechanisms of certain of our subsidiaries.

Regulatory effects of accounting for income taxes. Represents the deferral and under collection of deferred taxes in the rate making process.

Under-recovered gas and fuel costs. Represents the difference between the costs of gas and fuel, as well as energy acquired through power purchase agreements, including NIPSCO's own renewable projects, and the recovery of such costs in revenue and is used to adjust future billings for such deferrals on a basis consistent with applicable state-approved tariff provisions. Recovery of these costs is achieved through tracking mechanisms.

Depreciation. Represents differences between depreciation expense incurred on a GAAP basis and that prescribed through regulatory order. The majority of this balance is driven by Columbia of Ohio's IRP and CEP deferrals.

Post-in-service carrying charges. Represents deferred debt-based carrying charges incurred on certain assets placed into service but not yet included in customer rates. The majority of this balance is driven by Columbia of Ohio's IRP and CEP deferrals.

Safety activity costs. Represents the difference between costs incurred by certain of our subsidiaries in eligible safety programs in compliance with PHMSA regulations in excess of those being recovered in rates. The majority of this balance is driven by Columbia of Ohio.

DSM programs. Represents costs associated with Columbia Operations and NIPSCO Operations energy efficiency and conservation programs. Costs are recovered through tracking mechanisms.

Retired coal generating stations. Represents the net book value of Units 7 and 8 of Bailly Generating Station that was retired during 2018 and the net book value of Units 14 and 15 of R.M. Schahfer Generating Station retired in 2021. These amounts are currently being amortized at a rate consistent with their inclusion in customer rates. The August 2023 NIPSCO electric rate case order extends the recovery of, and on, the net book value of the stations by the end of 2034 and implements a revenue credit for the retired units. The credit is based on the difference between the year-end value of Units 14 and 15 and the most recent value established in the last base rate case proceeding or credit compliance filing.

Losses on commodity price risk programs. Represents the unrealized losses related to certain of our subsidiary's commodity price risk programs. These programs help to protect against the volatility of commodity prices and these amounts are collected from customers through their inclusion in customer rates.

Deferred property taxes. Represents the deferral and under collection of property taxes in the rate making process for Columbia of Ohio and is driven by the IRP and CEP deferrals.

Renewable energy investments. Represents the regulatory deferral of renewable energy formation and developer costs primarily through deferred depreciation.

WAM system filing. Represents the deferral of certain costs, including depreciation and amortization incurred in connection with improvements to its information technology systems through the design, development, and implementation of a new WAM program for the scheduling, dispatch, and execution of work and the management of underlying assets.

Customer Assistance Programs. Represents the difference between the eligible customer assistance program costs and collections, which will be collected from customers.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Uncollected Future Cost of Removal. Represents asset removal costs not yet recovered.

Liabilities:

Over-recovered gas and fuel costs. Represents the difference between the cost of gas and fuel, as well as energy acquired through power purchase agreements, including NIPSCO's own renewable projects and, the recovery of such costs in revenues and is the basis to adjust future billings for such refunds on a basis consistent with applicable state-approved tariff provisions. Refunding of these revenues is achieved through tracking mechanisms.

Cost of removal. Represents anticipated costs of removal for utility assets that have been collected through depreciation rates for future costs to be incurred.

Regulatory effects of accounting for income taxes. Represents amounts owed to customers for deferred taxes collected at a higher rate than the current statutory rates and liabilities associated with accelerated tax deductions owed to customers. Balance includes excess deferred taxes recorded upon implementation of the TCJA in December 2017, net of amounts amortized through 2025 and federal tax credits generated by Cavalry, Dunn's Bridge II, Fairbanks, and Gibson solar facilities that are passed back to customers. For discussion of the regulatory impact of the NIPSCO Minority Interest Transaction on deferred taxes, see Note 15, "Income Taxes," for additional details.

Deferred pension and other postretirement benefit costs. Primarily represents cash contributions in excess of postretirement benefit expense that is deferred by certain subsidiaries.

Gains on commodity price risk programs. Represents the unrealized gains related to certain of our subsidiary's commodity price risk programs. These programs help to protect against the volatility of commodity prices, and these amounts are passed back to customers through their inclusion in customer rates.

Customer Assistance Programs. Represents the difference between the eligible customer assistance program costs and collections, which will be refunded to customers.

Renewable energy investments. Represents the regulatory deferral of certain amounts representing the timing difference between the profit earned from the JVs and the amount included in regulated rates to recover our approved investments in consolidated JVs. The offset to the regulatory liability associated with our renewable investments is recorded in "Depreciation expense" on the Statements of Consolidated Comprehensive Income. Refer to Note 1, "Nature of Operations and Summary of Significant Accounting Policies - S. Noncontrolling Interest," Note 4, "Noncontrolling Interests," and Note 9, "Property, Plant and Equipment," for additional information.

Rate Refunds. Represents supplier refunds received by the company that are owed to customers and will be remitted and amounts that are being collected in rates subject to refund.

Off System Sales Sharing. Represents amounts to be passed back to the customers as a result of Off System sales that is shared between the company and the customer.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

13. Risk Management Activities

We are exposed to certain risks related to our ongoing business operations; namely commodity price risk and interest rate risk. We recognize that the prudent and selective use of derivatives may help to limit volatility in the price of natural gas, and manage interest rate exposure.

Risk management assets and liabilities on our derivatives are presented on the Consolidated Balance Sheets as shown below:

			December 31, 2025												December 31, 2024
(in millions)			Assets						Liabilities						Assets						Liabilities
Current(1)
Derivatives not designated as hedging instruments			$	9.7					$	2.1					$	9.1					$	2.3
Total			$	9.7					$	2.1					$	9.1					$	2.3
Noncurrent(2)
Derivatives not designated as hedging instruments			$	9.1					$	3.8					$	17.9					$	1.2
Total			$	9.1					$	3.8					$	17.9					$	1.2

(1) Current assets and liabilities are presented in "Prepayments and other" and "Other accruals", respectively, on the Consolidated Balance Sheets.

(2) Noncurrent assets and liabilities are presented in "Deferred charges and other" and "Other noncurrent liabilities and deferred credits", respectively, on the Consolidated Balance Sheets.

Our derivative instruments are subject to enforceable master netting arrangements or similar agreements. No collateral was either received or posted related to our outstanding derivative positions at December 31, 2025 and 2024. If the above gross asset and liability positions were presented net of amounts owed or receivable from counterparties, we would report a net asset position of $12.9 million and $23.5 million at December 31, 2025 and 2024, respectively.

Derivatives Not Designated as Hedging Instruments

Commodity price risk management. We, along with our utility customers, are exposed to variability in cash flows associated with natural gas purchases and volatility in natural gas prices. We purchase natural gas for sale and delivery to our retail, commercial and industrial customers, and for most customers the variability in the market price of gas is passed through in their rates. Some of our utility subsidiaries offer programs whereby variability in the market price of gas is assumed by the respective utility. The objective of our commodity price risk programs is to mitigate the gas cost variability, for us or on behalf of our customers, associated with natural gas purchases or sales by economically hedging the various gas cost components using a combination of futures, options, forwards or other derivative contracts. As of December 31, 2025 and 2024, we had 83.7 MMDth and 77.8 MMDth, respectively, of net energy derivative volumes outstanding related to our natural gas hedges.

NIPSCO has received IURC approval to lock in a fixed price for its natural gas customers using long-term forward purchase instruments and is limited to 20% of NIPSCO’s average annual GCA purchase volume. As of December 31, 2025, the remaining terms of these instruments range from one to three years. Likewise, Columbia of Pennsylvania has received approval for a 24-month rolling hedge program that will continue in perpetuity. The program is designed to financially hedge approximately 20% of the customer’s annual demand. Under both programs all gains and losses on these derivative contracts are deferred as regulatory liabilities or assets and are remitted to or collected from customers through the relevant cost recovery mechanism.

Derivatives Designated as Hedging Instruments

Interest rate risk management. As of December 31, 2025 and 2024, we had no active interest rate swap positions. We have recorded the overall net loss related to previously settled interest rate swaps in AOCI. The gain or loss associated with each previously settled interest rate swap is amortized in interest expense over the term of each corresponding debt issuance. These amounts were immaterial for the years ended December 31, 2025, 2024 and 2023 and are recorded in "Interest expense, net" on the Condensed Statements of Consolidated Income. Amounts expected to be reclassified to earnings during the next twelve months are immaterial. See Note 20, "Accumulated Other Comprehensive Loss," for additional information.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

14. Fair Value

**A.**Fair Value Measurements

Recurring Fair Value Measurements

The following tables present financial assets and liabilities measured and recorded at fair value on our Consolidated Balance Sheets on a recurring basis and their level within the fair value hierarchy as of December 31, 2025 and December 31, 2024. As of December 31, 2025 and December 31, 2024, there were no material transfers between fair value hierarchies. Additionally, there were no changes in the method or significant assumptions used to estimate the fair value of our financial instruments.

Recurring Fair Value Measurements December 31, 2025 (in millions)			Quoted Prices in Active Markets for Identical Assets (Level 1)						Significant Other Observable Inputs (Level 2)						Significant Unobservable Inputs (Level 3)						Balance as of December 31, 2025
Assets
Risk management assets			$	—					$	18.8					$	—					$	18.8
Available-for-sale debt securities			—						146.1						—						146.1
Equity Securities(1)(2)			8.5						—						—						8.5
Total			$	8.5					$	164.9					$	—					$	173.4
Liabilities
Risk management liabilities			$	—					$	5.9					$	—					$	5.9
Total			$	—					$	5.9					$	—					$	5.9

(1) Equity securities are in a high dividend equity fund and are valued using market prices in active markets. Level 1 instrument valuations are obtained from real-time quotes for transactions in active exchange markets involving identical assets. Equity securities are presented in "Other Investments" on the Consolidated Balance Sheets.

(2)As of December 31, 2025, the investment cost of equity securities measured at fair value was $7.9 million, gross unrealized gains were $0.7 million, and the fair value was $8.5 million.

Recurring Fair Value Measurements December 31, 2024 (in millions)			Quoted Prices in Active Markets for Identical Assets (Level 1)						Significant Other Observable Inputs (Level 2)						Significant Unobservable Inputs (Level 3)						Balance as of December 31, 2024
Assets
U.S. Treasury debt securities(1)			$	80.1					$	—					$	—					$	80.1
Risk management assets			—						27.0						—						27.0
Available-for-sale debt securities			—						86.7						—						86.7
Total			$	80.1					$	113.7					$	—					$	193.8
Liabilities
Risk management liabilities			$	—					$	3.5					$	—					$	3.5
Total			$	—					$	3.5					$	—					$	3.5

(1)Treasury bills are presented in "Cash and cash equivalents" and "Restricted cash" on the Consolidated Balance Sheets.

Level 1- When utilized, exchange-traded derivative contracts are based on unadjusted quoted prices in active markets and are classified within Level 1. These financial assets and liabilities are secured with cash on deposit with the exchange; therefore, nonperformance risk has not been incorporated into these valuations. These financial assets and liabilities are deemed to be cleared and settled daily by NYMEX as the related cash collateral is posted with the exchange. As a result of this exchange rule, NYMEX derivatives are considered to have no fair value at the balance sheet date for financial reporting purposes, and are presented in Level 1 net of posted cash; however, the derivatives remain outstanding and are subject to future commodity price fluctuations until they are settled in accordance with their contractual terms.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Level 2- Certain non-exchange-traded derivatives are valued using broker or over-the-counter, on-line exchanges. In such cases, these non-exchange-traded derivatives are classified within Level 2. Non-exchange-based derivative instruments include swaps, forwards, and options. In certain instances, these instruments may utilize models to measure fair value. We use a similar model to value similar instruments. Valuation models utilize various inputs that include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, other observable inputs for the asset or liability and market-corroborated inputs, (i.e., inputs derived principally from or corroborated by observable market data by correlation or other means). Where observable inputs are available for substantially the full term of the asset or liability, the instrument is categorized within Level 2.

Level 3- Certain derivatives trade in less active markets with a lower availability of pricing information and models may be utilized in the valuation. When such inputs have a significant impact on the measurement of fair value, the instrument is categorized within Level 3.

Risk Management Assets and Liabilities. Risk management assets and liabilities include exchange-traded NYMEX futures and NYMEX options and non-exchange-based forward purchase contracts. NIPSCO and Columbia of Pennsylvania have entered into long-term forward natural gas purchase instruments to lock in a fixed price for natural gas customers. We value these contracts using a pricing model that incorporates market-based information when available, as these instruments trade less frequently and are classified within Level 2 of the fair value hierarchy. For additional information, see Note 13, "Risk Management Activities."

Available-for-Sale Debt Securities. Available-for-sale debt securities are investments pledged as collateral for trust accounts related to our wholly-owned insurance company. We value U.S. Treasury, corporate debt and mortgage-backed securities using a matrix pricing model that incorporates market-based information. These securities trade less frequently and are classified within Level 2.

Our available-for-sale debt securities impairments are recognized periodically using an allowance approach. At each reporting date, we utilize a quantitative and qualitative review process to assess the impairment of available-for-sale debt securities at the individual security level. For securities in a loss position, we evaluate our intent to sell or whether it is more-likely-than-not that we will be required to sell the security prior to the recovery of its amortized cost. If either criteria is met, the loss is recognized in earnings immediately, with the offsetting entry to the carrying value of the security. If both criteria are not met, we perform an analysis to determine whether the unrealized loss is related to credit factors. The analysis focuses on a variety of factors that include, but are not limited to, downgrade on ratings of the security, defaults in the current reporting period or projected defaults in the future, the security's yield spread over treasuries, and other relevant market data. If the unrealized loss is not related to credit factors, it is included in other comprehensive income. If the unrealized loss is related to credit factors, the loss is recognized as credit loss expense in earnings during the period, with an offsetting entry to the allowance for credit losses. The amount of the credit loss recorded to the allowance account is limited by the amount at which the security's fair value is less than its amortized cost basis. If certain amounts recorded in the allowance for credit losses are deemed uncollectible, the allowance on the uncollectible portion will be charged off, with an offsetting entry to the carrying value of the security. Subsequent improvements to the estimated credit losses of available-for-sale debt securities will be recognized immediately in earnings. Continuous credit monitoring and portfolio credit balancing mitigates our risk of credit losses on our available-for-sale debt securities.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

The amortized cost, gross unrealized gains and losses, allowance for credit losses, and fair value of available-for-sale securities at December 31, 2025 and 2024 were:

December 31, 2025 (in millions)			Amortized Cost						Gross Unrealized Gains						Gross Unrealized Losses**(1)**						Allowance for Credit Losses						Fair Value
Available-for-sale debt securities
U.S. Treasury debt securities			$	9.5					$	—					$	—					$	—					$	9.5
Corporate/Other debt securities			136.3						2.4						(2.1)						—						136.6
Total			$	145.8					$	2.4					$	(2.1)					$	—					$	146.1
December 31, 2024 (in millions)			Amortized Cost						Gross Unrealized Gains						Gross Unrealized Losses**(2)**						Allowance for Credit Losses						Fair Value
Available-for-sale debt securities
Corporate/Other debt securities			91.9						0.5						(5.6)						(0.1)						86.7
Total			$	91.9					$	0.5					$	(5.6)					$	(0.1)					$	86.7

(1) Fair value of U.S. Treasury debt securities and Corporate/Other debt securities in an unrealized loss position without an allowance for credit losses is $3.5 million and $40.2 million, respectively at December 31, 2025.

(2) Fair value of Corporate/Other debt securities in an unrealized loss position without an allowance for credit losses is $70.1 million at December 31, 2024.

The cost of maturities sold is based upon specific identification. Net realized gains and losses on available-for-sale securities were $(1.0) million for the twelve months ended December 31, 2025, and $2.3 million for the twelve months ended December 31, 2024. At December 31, 2025, approximately $9.8 million and $4.0 million of of Corporate/Other debt securities and U.S. Treasury debt securities, respectively, have maturities of less than a year.

Equity Investments. Investments measured at net asset value per share (or its equivalent) as a practical expedient have not been classified in the fair value hierarchy. These investments represent holdings in a single private investment fund that are redeemable at the election of the holder. As of December 31, 2025, the Company holds $17.9 million of equity investments measured at net asset value.

Non-recurring Fair Value Measurements

We measure the fair value of certain assets, including goodwill, on a non-recurring basis, typically when events or changes in circumstances indicate that the carrying amount of the assets may not be recoverable. As of December 31, 2025, no non-recurring fair value adjustments have been made.

B. Other Fair Value Disclosures for Financial Instruments.

The carrying amount of cash and cash equivalents, restricted cash, notes receivable, customer deposits and short-term borrowings is a reasonable estimate of fair value due to their liquid or short-term nature. Our long-term borrowings are recorded at historical amounts.

The following method and assumptions were used to estimate the fair value of each class of financial instruments.

Long-term debt. The fair value of outstanding long-term debt is estimated based on the quoted market prices for the same or similar securities. Certain premium costs associated with the early settlement of long-term debt are not taken into consideration in determining fair value. These fair value measurements are classified within Level 2 of the fair value hierarchy. For the years ended December 31, 2025 and 2024, there was no change in the method or significant assumptions used to estimate the fair value of long-term debt.

The carrying amount and estimated fair values of these financial instruments were as follows:

At December 31, (in millions)			Carrying Amount 2025						Estimated Fair Value 2025						Carrying Amount 2024						Estimated Fair Value 2024
Long-term debt (including current portion)			$	15,477.5					$	14,975.3					$	13,355.7					$	12,505.2

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

15. Income Taxes

Judgment and the use of estimates are required in developing the provision for income taxes and reporting of tax-related assets and liabilities. The interpretation of tax laws and associated regulations involves uncertainty as taxing authorities may interpret the laws differently.

NIPSCO’s historical business activities through the closing of the NIPSCO Minority Interest Transaction in 2023 were included in the consolidated U.S. federal and certain state income tax returns of NiSource Inc. Prior to April 13, 2023, NIPSCO was treated as a taxable division of its corporate parent, NiSource Inc. Beginning on that date, NIPSCO became a division of NIPSCO Holdings I. In connection with the NIPSCO Minority Interest Transaction, NIPSCO Holdings I retained NIPSCO’s income tax balances and 80.1% of the excess deferred income tax regulatory balances as described below. NIPSCO Holdings I’s income tax balances are based on the difference between the financial statement amount and the tax basis of its investment in NIPSCO Holdings II.

Income Tax Expense. The components of income tax expense (benefit) were as follows:

Year Ended December 31, (in millions)			2025						2024						2023
Income Taxes
Current
Federal			$	(30.4)					$	(19.3)					$	—
State			(1.6)						9.4						5.3
Total Current (Benefit) Expense			(32.0)						(9.9)						5.3
Deferred
Federal
Taxes before operating loss carryforwards and investment credits			189.2						105.9						49.7
Tax utilization expense of operating loss carryforwards			34.2						60.4						65.1
Investment tax credits			—						(0.1)						(2.1)
State			13.1						2.6						22.5
Total Deferred Expense			236.5						168.8						135.2
Deferred Investment Tax Credits			(0.7)						(0.8)						(1.0)
Income Taxes from Continuing Operations			$	203.8					$	158.1					$	139.5

We earn federal Investment Tax Credits ("ITC"s) and Production Tax Credits ("PTC"s) related to qualifying renewable energy projects. These credits are nonrefundable, can be utilized to offset income tax liabilities, and are transferable. We recognize the benefit of these credits within income tax expense (benefit) in the period the credits are generated.

During the periods ended December 31, 2025 and 2024, respectively, we elected to monetize certain transferable ITC/PTC credits through sales to unrelated third‑party taxpayers. Accordingly, the cash proceeds received from the sale of the credits are reflected as an adjustment to income tax (benefit) expense. We recognized a current tax benefit associated with the monetization of these credits of $19.3 million and $18.8 million, for the years ended December 31, 2025, and 2024, respectively. These amounts offset current tax expense in the years received and a regulatory liability was established to pass back to customers over ten years, as ordered by the regulator.

In connection with the NIPSCO Minority Interest Transaction during 2023, NiSource recognized a $63.5 million income tax benefit in additional paid in capital related to 19.9% of NIPSCO’s excess deferred income taxes attributable to Blackstone’s noncontrolling interest. This benefit does not impact NIPSCO’s regulatory books or the excess deferred taxes that will benefit customers through lower future rates in accordance with applicable regulatory orders. See Note 4, "Noncontrolling Interests," for further discussion of the NIPSCO Minority Interest Transaction.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Statutory Rate Reconciliation. The following table provides a quantitative reconciliation of the reported income tax expense (benefit) from the statutory U.S. federal income tax rate to the Company's effective tax rate for each period presented.

Year Ended December 31, (in millions)			2025												2024												2023
Book income before income taxes			$	1,216.4											$	1,002.8											$	813.9
Tax expense (benefit) at statutory federal income tax rate			255.4						21.0		%				210.6						21.0		%				170.8						21.0		%
State and local income taxes, net of federal income tax effect			4.9						0.4						11.7						1.2						13.7						1.7
Tax Credits
Investment tax credit			(32.4)						(2.7)						(14.5)						(1.5)						(2.1)						(0.3)
Production tax credit			(40.5)						(3.3)						(5.8)						(0.6)						(0.3)						—
Other			(3.1)						(0.3)						(3.0)						(0.3)						(1.5)						(0.2)
Regulatory Adjustments
ITC / PTC			68.2						5.6						20.0						2.0						—						—
Amortization of Excess Deferred Income Taxes			(30.2)						(2.5)						(31.2)						(3.1)						(39.2)						(4.8)
AFUDC equity			(5.5)						(0.4)						(12.5)						(1.2)						(5.3)						(0.7)
Changes in Valuation Allowances			8.4						0.7						—						—						—						—
Nontaxable or Nondeductible Items
Noncontrolling interests			(18.2)						(1.5)						(27.3)						(2.7)						—						—
Other			1.2						0.1						7.6						0.8						7.8						0.9
Other adjustments			(4.4)						(0.3)						2.5						0.2						(4.4)						(0.5)
Income Taxes			$	203.8					16.8		%				$	158.1					15.8		%				$	139.5					17.1		%

For the year ended December 31, 2025, the state and local income tax reconciling item of $4.9 million represents the tax effect of income primarily in Virginia, which accounted for more than 50 percent of the company's state and local tax liability.

The increase in tax expense of $45.7 million in 2025 versus 2024 was primarily due to higher pre-tax income, the establishment of a valuation allowance on deferred tax assets related to disallowed §163(j) interest carryforwards, lower non-controlling interest and lower AFUDC equity, partially offset by lower state taxes and higher federal investment and production credits generated by Dunns Bridge II Solar and Storage facility, Cavalry Solar, Fairbanks Solar, and Gibson Solar that are offset in a regulatory liability to pass back to customers in future periods.

The increase in the ITC / PTC regulatory adjustment in 2025 versus 2024 was primarily due to the regulatory liability established for the investment and production tax credits generated in 2025, net of the $4.6 million pass back to customers of prior period federal tax credits.

The increase in tax expense of $18.6 million in 2024 versus 2023 was primarily due to higher pre-tax income, partially offset by the tax effect of non-controlling interest, and higher federal tax credits generated by the Cavalry solar and storage facility that are offset in a regulatory liability to pass back to customers in future periods.

The increase in the ITC / PTC regulatory adjustment in 2024 versus 2023 was primarily due to the regulatory liability established for the Cavalry tax credits generated in 2024.

Cash Taxes Paid Disclosure. In accordance with ASU 2023-09, the following table provides cash taxes paid for each period presented, which represents the actual cash payments made for income taxes to federal and state authorities by jurisdiction and differs from the income tax expense recognized for financial reporting purposes due to deferred taxes, credits, and other reconciling items.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Year Ended December 31, (in millions)			2025						2024						2023
Jurisdiction
Federal			$	2.5					$	—					$	—
Pennsylvania			(0.2)						3.0						4.0
Virginia			—						1.2						5.4
Ohio local			0.7						—						—
Other			0.3						0.1						—
Total Cash Taxes Paid			$	3.3					$	4.3					$	9.4

The state component for 2025 and prior years primarily relates to Pennsylvania, Virginia and local Ohio taxes, accounting for greater than 50 percent of the total state tax payments.

Net Deferred Income Tax Liability Components. Deferred income taxes result from temporary differences between the financial statement carrying amounts and the tax basis of existing assets and liabilities. The principal components of our net deferred tax liabilities were as follows:

At December 31, (in millions)			2025						2024
Deferred tax liabilities
Accelerated depreciation and other property differences			$	1,552.0					$	1,419.4
Partnership basis differences			1,431.1						1,328.6
Other regulatory assets			210.3						210.1
Total Deferred Tax Liabilities			3,193.4						2,958.1
Deferred tax assets
Other regulatory liabilities and deferred investment tax credits (including TCJA)			185.1						170.4
Pension and other postretirement/postemployment benefits			32.0						58.8
Net operating loss carryforwards			326.0						369.4
Environmental liabilities			10.3						12.2
Other accrued liabilities			49.6						43.4
Disallowed §163(j) interest expense carryforward			8.4						—
General business credits			77.3						20.5
Other, net			19.4						8.2
Total Deferred Tax Assets			708.1						682.9
Valuation Allowance			(14.8)						(6.4)
Net Deferred Tax Assets			693.3						676.5
Net Deferred Tax Liabilities			$	2,500.1					$	2,281.6

Deferred tax assets include amounts for disallowed §163(j) interest expense carryforward; during the period, we recorded a valuation allowance on these amounts in accordance with realizability requirements, and corresponds to the unfavorable item presented in the rate reconciliation.

On April 14, 2023, the IRS issued Revenue Procedure 2023-15 which provides a safe harbor method of accounting that taxpayers may use to determine whether expenses to repair, maintain, replace, or improve linear property and non-linear natural gas transmission and distribution property must be capitalized as improvements or are allowable as deductions. On June 3, 2024, the IRS extended the favorable rules to a Year 2 adoption period. The Company filed a method change with its 2024 consolidated tax return filing to elect this change in tax accounting method under the cutoff method.

In connection with the NIPSCO Minority Interest Transaction, NIPSCO’s deferred taxes were removed from its GAAP books and were reconstituted as deferred taxes on the outside basis difference of NiSource’s investment in NIPSCO Holdings II. These deferred taxes are reflected as partnership basis differences above.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

NiSource has the following deductible loss and credit carryforwards:

At December 31, 2025 (in millions)			Deductible Amount						Deferred Tax Asset						Valuation Allowance						Expiration Period
Federal losses			$	1,192.0					$	250.3					$	—					Indefinite
Federal investment tax credits			—						31.0						—						2043-2045
Federal production tax credits			—						23.4						—						2040-2045
Federal other credit			—						22.9						—						2029-2045
Federal disallowed interest expense carryforward			—						8.4						(8.4)						Indefinite
State losses			1,867.1						75.4						(6.4)						2029-2045
Total									$	411.4					$	(14.8)

We believe it is not more likely than not that the Federal §163(j) disallowed interest expense carryforward and a portion of the benefit from certain state net operating loss carryforwards will be realized. We have recorded a valuation allowance of $8.4 million on the deferred tax asset related to the Federal §163(j) interest expense carryforward and $6.4 million related to Massachusetts Net Operating Losses reflected in table presented above.

Unrecognized Tax Benefits. A reconciliation of the beginning and ending amounts of unrecognized tax benefits is as follows:

At December, (in millions)			2025						2024						2023
Opening Balance			$	21.7					$	21.7					$	21.7
Gross decreases - tax positions in prior period			—						—						—
Gross increases - current period tax positions			—						—						—
Ending Balance			$	21.7					$	21.7					$	21.7
Offset for net operating loss carryforwards			(21.7)						(21.7)						(21.7)
Balance, Less Net Operating Loss Carryforwards			$	—					$	—					$	—

We are subject to income taxation in the United States and various state jurisdictions, primarily Indiana, Pennsylvania, Kentucky, Massachusetts, Maryland and Virginia.

We participate in the IRS CAP, which provides the opportunity to resolve tax matters with the IRS before filing each year's consolidated federal income tax return. As of December 31, 2025, tax years through 2023 have been audited and are closed to further assessment. NiSource has not yet received a final acceptance letter from the IRS for its 2024 return. However, no adjustments are expected.

The statute of limitations in each of the state jurisdictions in which we operate remains open between 3-4 years from the date the state income tax returns are filed. As of December 31, 2025, there were no state income tax audits in progress that would have a material impact on the consolidated financial statements.

NiSource is obligated to report adjustments resulting from IRS audits or settlements to state taxing authorities. In addition, if NiSource utilizes net operating losses or tax credits generated in years for which the statute of limitations has expired, such amounts are generally subject to examination.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

16. Pension and Other Postemployment Benefits

We provide defined contribution plans and noncontributory defined benefit retirement plans that cover certain of our employees. Benefits under the defined benefit retirement plans reflect the employees’ compensation, years of service and age at retirement. Additionally, we provide health care and life insurance benefits for certain retired employees. Certain employees may become eligible for these benefits if they reach retirement age while working for us. The expected cost of such benefits is accrued during the employees’ years of service. Current rates of rate-regulated companies include postretirement benefit costs, including amortization of the regulatory assets that arose prior to inclusion of these costs in rates. For most plans, cash contributions are remitted to grantor trusts.

Our Pension and Other Postretirement Benefit Plans’ Asset Management. The Board has delegated oversight of the pension and other postretirement benefit plans’ assets to the NiSource Benefits Committee (the "Committee"). The Committee has adopted investment policy statements for the pension and other postretirement benefit plans’ assets. For the pension plans, we employ a liability-driven investing strategy. A total return approach is utilized for some of the other postretirement benefit plans’ assets. A mix of diversified investments are used to maximize the long-term return of plan assets and hedge the liabilities at a prudent level of risk. The investment portfolio includes U.S. and non-U.S. equities, real estate, long-term and intermediate-term fixed income and alternative investments. Risk tolerance is established through careful consideration of plan liabilities, funded status, and asset class volatility. Investment risk is measured and monitored on an ongoing basis through quarterly investment portfolio reviews, annual liability measurements, and periodic asset/liability studies.

In determining the expected long-term rate of return on plan assets, historical markets are studied, relationships between equities and fixed income are analyzed and current market factors, such as inflation and interest rates are evaluated with consideration of diversification and rebalancing. Our expected long-term rate of return on assets is based on assumptions regarding target asset allocations and corresponding long-term capital market assumptions for each asset class. The pension plans’ investment policy calls for a gradual reduction in the allocation of return-seeking assets (equities, real estate and private equity) and a corresponding increase in the allocation of liability-hedging assets (fixed income) as the funded status of the plans’ increase.

As of December 31, 2025 and December 31, 2024, the acceptable minimum and maximum ranges established by the policy for the pension and other postretirement benefit plans are as follows:

December 31, 2025			Defined Benefit Pension Plan												Postretirement Benefit Plan
Asset Category			Minimum						Maximum						Minimum						Maximum
Domestic Equities			10%						30%						0%						55%
International Equities			5%						15%						0%						25%
Fixed Income			65%						75%						20%						100%
Private Equity			0%						3%						0%						0%
Short-Term Investments			0%						10%						0%						10%

December 31, 2024			Defined Benefit Pension Plan												Postretirement Benefit Plan
Asset Category			Minimum						Maximum						Minimum						Maximum
Domestic Equities			10%						30%						0%						55%
International Equities			5%						15%						0%						25%
Fixed Income			65%						75%						20%						100%
Private Equity			0%						3%						0%						0%
Short-Term Investments			0%						10%						0%						10%

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

The actual Pension Plan and Postretirement Plan Asset Mix at December 31, 2025 and December 31, 2024 are as follows:

			Defined Benefit Pension Assets(1)						December 31, 2025						Postretirement Benefit Plan Assets						December 31, 2025
Asset Class (in millions)			Asset Value						% of Total Assets						Asset Value						% of Total Assets
Domestic Equities			$	270.0					20.2		%				$	105.4					40.8		%
International Equities			137.5						10.3		%				48.8						18.9		%
Fixed Income			869.0						64.9		%				99.2						38.5		%
Cash/Other			61.9						4.6		%				4.6						1.8		%
Total			$	1,338.4					100.0		%				$	258.0					100.0		%
(1)Total includes accrued dividends and pending trades with brokers.
			Defined Benefit Pension Assets(1)						December 31, 2024						Postretirement Benefit Plan Assets(1)						December 31, 2024
Asset Class (in millions)			Asset Value						% of Total Assets						Asset Value						% of Total Assets
Domestic Equities			$	258.9					19.4		%				$	99.6					40.9		%
International Equities			122.5						9.2		%				40.7						16.7		%
Fixed Income			891.2						66.7		%				96.5						39.6		%
Real Estate			4.0						0.3		%				—						—
Cash/Other			59.8						4.4		%				6.7						2.8		%
Total			$	1,336.4					100.0		%				$	243.5					100.0		%

(1)Total includes accrued dividends and pending trades with brokers.

The categorization of investments into the asset classes in the tables above are based on definitions established by the Committee.

Fair Value Measurements. The following table sets forth, by level within the fair value hierarchy, the pension and other postretirement benefits investment assets at fair value as of December 31, 2025 and 2024. Assets are classified in their entirety based on the observability of inputs used in determining the fair value measurement. There were no material investment assets in the pension and other postretirement benefits trusts classified within Level 3 for the years ended December 31, 2025 and 2024.

We use the following valuation techniques to determine fair value. For the year ended December 31, 2025, there were no significant changes to valuation techniques to determine the fair value of our pension and other postretirement benefits' assets.

Level 1 Measurements

Most common and preferred stocks are traded in active markets on national and international securities exchanges and are valued at closing prices on the last business day of each period presented. Cash is stated at cost, which approximates fair value, with the exception of cash held in foreign currencies which fluctuates with changes in the exchange rates. Short-term bills and notes are priced based on quoted market values.

Level 2 Measurements

Most U.S. Government Agency obligations, mortgage/asset-backed securities, and corporate fixed income securities are generally valued by benchmarking model-derived prices to quoted market prices and trade data for identical or comparable securities. To the extent that quoted prices are not available, fair value is determined based on a valuation model that includes inputs such as interest rate yield curves and credit spreads. Securities traded in markets that are not considered active are valued based on quoted market prices, broker or dealer quotations, or alternative pricing sources with reasonable levels of price transparency. Other fixed income includes futures and options which are priced on bid valuation or settlement pricing.

Level 3 Measurements

Investments with unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets and liabilities are classified as level 3 investments.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Not Classified

Commingled funds, private equity limited partnerships and real estate partnerships are not classified within the fair value hierarchy. Instead, these assets are measured at estimated fair value using the net asset value per share of the investments. Commingled funds' underlying assets are principally marketable equity and fixed income securities. Units held in commingled funds are valued at the unit value as reported by the investment managers. Private equity funds invest capital in non-public companies and real estate funds invest in commercial and distressed real estate directly or through related debt instruments. The fair value of these investments is determined by reference to the funds’ underlying assets.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Fair Value Measurements at December 31, 2025:

(in millions)			December 31, 2025						Quoted Prices in Active Markets for Identical Assets (Level 1)						Significant Other Observable Inputs (Level 2)						Significant Unobservable Inputs (Level 3)
Pension plan assets:
Cash			$	0.5					$	0.5					$	—					$	—
Fixed income securities
Government			197.1						—						197.1						—
Corporate			471.5						—						471.5						—
Mortgages/ Asset Backed Securities			3.9						—						3.9						—
Other fixed income			0.1						—						0.1						—
Derivatives
Assets			0.6						—						0.6						—
Mutual Funds
U.S. multi-strategy			53.9						53.9						—						—
International equities			34.0						34.0						—						—
Private equity limited partnerships(1)
U.S. multi-strategy(2)			2.4						—						—						—
International multi-strategy(3)			0.2						—						—						—
Distressed opportunities			0.1						—						—						—
Real estate(1)			—						—						—						—
Commingled funds(1)
Short-term money markets			50.1						—						—						—
U.S. equities			216.1						—						—						—
International equities			103.6						—						—						—
Fixed income			196.5						—						—						—
Pension plan assets subtotal			$	1,330.6					$	88.4					$	673.2					$	—
Other postretirement benefit plan assets:
Mutual funds
U.S. multi-strategy			92.4						92.4						—						—
International equities			16.8						16.8						—						—
Fixed income			99.2						99.2						—						—
Commingled funds(1)
Short-term money markets			4.6						—						—						—
U.S. equities			13.0						—						—						—
International equities			32.1						—						—						—
Other postretirement benefit plan assets subtotal			$	258.1					$	208.4					$	—					$	—
Due to brokers, net(4)			(0.6)						—						(0.6)						—
Accrued income/dividends			8.3						8.3												—
Total pension and other postretirement benefit plan assets			$	1,596.4					$	305.1					$	672.6					$	—

(1))This class of investments is measured at fair value using the net asset value per share and has not been classified in the fair value hierarchy.

(2)This class includes limited partnerships that invest in a diverse portfolio of private equity strategies, including buy-outs, growth capital, special situations and secondary markets, primarily inside the United States.

(3)This class includes limited partnerships that invest a in diverse portfolio of private equity strategies, including buy-outs, growth capital, special situations and secondary markets, primarily outside the United States.

(4)This class represents pending trades with brokers.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

The table below sets forth a summary of unfunded commitments, redemption frequency and redemption notice periods for certain investments that are measured at fair value using the net asset value per share for the year ended December 31, 2025:

(in millions)			Fair Value						Unfunded Commitments						Redemption Frequency						Redemption Notice Period
Commingled Funds
Short-term money markets			$	54.7					$	—					Daily						1 day
U.S. equities			229.1						—						Daily						1 day - 10 days
International equities			135.7						—						Monthly						1 day-10 days
Fixed income			196.5						—						Daily						2 days
Private Equity and Real Estate Limited Partnerships(1)			2.7						9.3						N/A						N/A
Total			$	618.7					$	9.3

(1)Private equity and real estate limited partnerships typically call capital over a 3-5 year period and pay out distributions as the underlying investments are liquidated. The typical expected life of these limited partnerships is 0-15 years, and these investments typically cannot be redeemed prior to liquidation.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Fair Value Measurements at December 31, 2024:

(in millions)			December 31, 2024						Quoted Prices in Active Markets for Identical Assets (Level 1)						Significant Other Observable Inputs (Level 2)						Significant Unobservable Inputs (Level 3)
Pension plan assets:
Cash			$	1.2					$	1.1					$	0.1					$	—
Fixed income securities
Government			186.8						—						186.8						—
Corporate			486.6						—						486.6						—
Mortgages/Asset backed securities			3.6						—						3.6						—
Mutual Funds
U.S. multi-strategy			56.1						56.1						—						—
International equities			57.2						57.2						—						—
Private equity limited partnerships(1)
U.S. multi-strategy(2)			3.1						—						—						—
International multi-strategy(3)			0.8						—						—						—
Distressed opportunities			0.1						—						—						—
Real estate(1)			4.0						—						—						—
Commingled funds(1)
Short-term money markets			45.9						—						—						—
U.S. equities			202.8						—						—						—
International equities			65.3						—						—						—
Fixed income			214.1						—						—						—
Pension plan assets subtotal			$	1,327.6					$	114.4					$	677.1					$	—
Other postretirement benefit plan assets:
Mutual funds
U.S. multi-strategy			87.4						87.4						—						—
International equities			16.5						16.5						—						—
Fixed income			96.5						96.5						—						—
Commingled funds(1)
Short-term money markets			6.7						—						—						—
U.S. equities			12.2						—						—						—
International equities			24.2						—						—						—
Other postretirement benefit plan assets subtotal			$	243.5					$	200.4					$	—					$	—
Due to brokers, net(4)			(0.1)						—						(0.1)						—
Accrued income/dividends			8.9						8.9						—						—
Total pension and other postretirement benefit plan assets			$	1,579.9					$	323.7					$	677.0					$	—

(1)This class of investments is measured at fair value using the net asset value per share and has not been classified in the fair value hierarchy.

(2)This class includes limited partnerships/fund of funds that invest in a diverse portfolio of private equity strategies, including buy-outs, growth capital, special situations and secondary markets, primarily inside the United States.

(3)This class includes limited partnerships/fund of funds that invest in diverse portfolio of private equity strategies, including buy-outs, growth capital, special situations and secondary markets, primarily outside the United States.

(4)This class represents pending trades with brokers.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

The table below sets forth a summary of unfunded commitments, redemption frequency and redemption notice periods for certain investments that are measured at fair value using the net asset value per share for the year ended December 31, 2024:

(in millions)			Fair Value												Redemption Frequency						Redemption Notice Period
Commingled Funds
Short-term money markets			$	52.6											Daily						1 day
U.S. equities			215.0												Daily						1 day -5 days
International equities			89.5												Monthly						10 days - 30 days
Fixed income			214.1												Daily						3 days
Private Equity and Real Estate Limited Partnerships(1)			8.0												N/A						N/A
Total			$	579.2

(1)Private equity and real estate limited partnerships typically call capital over a 3-5 year period and pay out distributions as the underlying investments are liquidated. The typical expected life of these limited partnerships is 0-15 years, and these investments typically cannot be redeemed prior to liquidation.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Our Pension and Other Postretirement Benefit Plans’ Funded Status and Related Disclosure. The following table provides a reconciliation of the plans’ funded status and amounts reflected in our Consolidated Balance Sheets at December 31 based on a December 31 measurement date:

			Pension Benefits												Other Postretirement Benefits
(in millions)			2025						2024						2025						2024
Change in projected benefit obligation**(1)**
Benefit obligation at beginning of year			$	1,287.4					$	1,401.8					$	436.3					$	468.8
Service cost			19.7						21.9						4.0						5.0
Interest cost			64.1						64.9						21.6						22.0
Plan participants’ contributions			—						—						4.0						3.6
Plan amendments			—						—						(30.3)						—
Actuarial loss (gain)(2)			34.8						(64.8)						(1.8)						(22.5)
Benefits paid			(135.2)						(136.4)						(39.0)						(40.7)
Estimated benefits paid by incurred subsidy			—						—						0.1						0.1
Projected benefit obligation at end of year			$	1,270.8					$	1,287.4					$	394.9					$	436.3
Change in plan assets
Fair value of plan assets at beginning of year			$	1,336.5					$	1,426.8					$	243.2					$	236.5
Actual return on plan assets			132.8						43.7						28.7						20.0
Employer contributions			2.0						2.4						20.7						23.6
Plan participants’ contributions			—						—						4.0						3.8
Benefits paid			(135.2)						(136.4)						(39.0)						(40.7)
Fair value of plan assets at end of year			$	1,336.1					$	1,336.5					$	257.6					$	243.2
Funded Status at end of year			$	65.3					$	49.1					$	(137.3)					$	(193.1)
Amounts recognized in the statement of financial position consist of:
Noncurrent assets			$	82.8					$	66.5					$	0.5					$	—
Current liabilities			(2.6)						(2.3)						(1.0)						(1.0)
Noncurrent liabilities			(14.9)						(15.1)						(136.8)						(192.1)
Net amount recognized at end of year**(3)**			$	65.3					$	49.1					$	(137.3)					$	(193.1)
Amounts recognized in accumulated other comprehensive income or regulatory asset/liability**(4)**
Unrecognized prior service credit			$	0.2					$	0.3					$	(23.8)					$	3.8
Unrecognized actuarial loss			413.8						451.4						28.1						47.0
Net amount recognized at end of year			$	414.0					$	451.7					$	4.3					$	50.8

(1)The change in benefit obligation for Pension Benefits represents the change in Projected Benefit Obligation while the change in benefit obligation for Other Postretirement Benefits represents the change in accumulated postretirement benefit obligation.

(2)The pension actuarial loss (gain) as of December 31, 2025 and December 31, 2024 was primarily driven by the decrease in discount rates interest rate movements and the increase in discount rates interest rate movements, respectively. The postretirement benefit actuarial (gain) as of December 31, 2025 and December 31, 2024 was primarily driven by claims experience changes in trend rates.

(3)We recognize our Consolidated Balance Sheets underfunded and overfunded status of our various defined benefit postretirement plans, measured as the difference between the fair value of the plan assets and the benefit obligation.

(4)We determined that for certain rate-regulated subsidiaries the future recovery of pension and other postretirement benefits costs is probable. These rate-regulated subsidiaries recorded regulatory assets and liabilities of $433.1 million and zero, respectively, as of December 31, 2025, and $485.3 million and zero, respectively, as of December 31, 2024 that would otherwise have been recorded to accumulated other comprehensive loss.

Our accumulated benefit obligation for our pension plans was $1,263.0 million and $1,278.4 million as of December 31, 2025 and 2024, respectively. The accumulated benefit obligation at each date is the actuarial present value of benefits attributed by the pension benefit formula to employee service rendered prior to that date and based on current and past compensation levels. The accumulated benefit obligation differs from the projected benefit obligation disclosed in the table above in that it includes no assumptions about future compensation levels.

We are required to reflect the funded status of our pension and postretirement benefit plans on the Consolidated Balance Sheet. We present the noncurrent aggregate of all underfunded plans within "Accrued liability for postretirement and postemployment benefits." The portion of the amount by which the actuarial present value of benefits included in the projected benefit obligation exceeds the fair value of plan assets, payable in the next 12 months, is reflected in "Accrued compensation and other benefits." We present the aggregate of all overfunded plans within "Deferred charges and other."

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

For our pension plans as of December 31, 2025 and 2024, only our nonqualified plans were underfunded. These plans have no assets as they are not funded until benefits are paid. The following table sets forth the year end accumulated benefit obligation and projected benefit obligation for pension plans with a projected benefit obligation in excess of plan assets:

			December 31,
(in millions)			2025						2024
Accumulated Benefit Obligation			$	17.5					$	17.4
Funded Status
Projected Benefit Obligation			$	17.5					$	17.4
Funded Status of Underfunded Pension Plans at End of Year			$	(17.5)					$	(17.4)

The following table sets forth the year end accumulated benefit obligation, projected benefit obligation and fair value of plan assets for pension plans with plan assets in excess of the projected benefit obligation:

			December 31,
(in millions)			2025						2024
Accumulated Benefit Obligation			$	1,245.5					$	1,261.0
Funded Status
Fair Value of Plan Assets			$	1,336.1					$	1,336.4
Projected Benefit Obligation			1,253.3						1,269.9
Funded Status of Overfunded Pension Plans at End of Year			$	82.8					$	66.5

Our pension plans were overfunded, in aggregate, by $65.3 million at December 31, 2025 compared to being overfunded by $49.1 million at December 31, 2024. The improvement in the funded status was primarily due to actual return on assets exceeding the expected return on assets, partially offset by a decrease in discount rates. We contributed $2.0 million and $2.4 million to our pension plans in 2025 and 2024, respectively.

Our other postretirement benefit plans were underfunded, in aggregate by $137.3 million and $193.1 million at December 31, 2025 and 2024, respectively. The change in funded status was primarily due to actual return on assets exceeding the expected return on assets, partially offset by a decrease in discount rates. We contributed $20.7 million and $23.6 million to our other postretirement benefit plans in 2025 and 2024, respectively.

In 2025 and 2024, our Columbia Energy Group pension plan paid lump sum payouts in excess of the respective plan's service cost plus interest cost, thereby meeting the requirement for settlement accounting. We recorded settlement charges of $6.5 million and $7.2 million in 2025 and 2024, respectively. In 2025 and 2024, no remeasurement occurred related to lump sum payouts.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

The following table provides the key assumptions that were used to calculate the pension and other postretirement benefits obligations for our various plans as of December 31:

			Pension Benefits												Other Postretirement Benefits
			2025						2024						2025						2024
Weighted-average assumptions to Determine Benefit Obligation
Discount Rate			5.28		%				5.58		%				5.45		%				5.66		%
Rate of Compensation Increases			4.00		%				4.00		%				N/A						N/A
Interest Crediting Rates			4.00		%				4.00		%				N/A						N/A
Health Care Trend Rates
Trend for Next Year			N/A						N/A						9.52		%				9.77		%
Ultimate Trend			N/A						N/A						4.75		%				4.75		%
Year Ultimate Trend Reached			N/A						N/A						2034						2033

We expect to make contributions of approximately $2.7 million to our pension plans and approximately $18.3 million to our postretirement medical and life plans in 2026.

The following table provides benefits expected to be paid in each of the next five fiscal years, and in the aggregate for the five fiscal years thereafter. The expected benefits are estimated based on the same assumptions used to measure our benefit obligation at the end of the year and include benefits attributable to the estimated future service of employees:

(in millions)			Pension Benefits						Other Postretirement Benefits
Year(s)
2026			$	151.9					$	31.4
2027			130.3						31.3
2028			126.6						31.1
2029			119.4						31.0
2030			115.7						31.2
2031-2035			510.7						152.9

The following table provides the components of the plans’ actuarially determined net periodic benefits cost for each of the three years ended December 31, 2025, 2024 and 2023:

			Pension Benefits																		Other Postretirement Benefits
(in millions)			2025						2024						2023						2025						2024						2023
Components of Net Periodic Benefit (Income) Cost(1)
Service cost			$	19.7					$	21.9					$	20.5					$	4.0					$	5.0					$	5.1
Interest cost			64.1						64.9						68.4						21.6						22.0						21.8
Expected return on assets			(92.4)						(95.3)						(94.5)						(16.8)						(16.1)						(15.1)
Amortization of prior service cost (credit)			0.1						0.1						0.1						(2.6)						(1.8)						(2.1)
Recognized actuarial loss			25.5						28.6						33.7						1.7						3.2						3.3
One-time charge			6.5						7.2						9.2						3.5						—						—
Total Net Periodic Benefits Cost			$	23.5					$	27.4					$	37.4					$	11.4					$	12.3					$	13.0

(1)Service cost is presented in "Operation and maintenance" on the Statements of Consolidated Income. Non-service cost components are presented within "Other, net."

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

The following table provides the key assumptions that were used to calculate the net periodic benefits cost for our various plans:

			Pension Benefits																		Other Postretirement Benefits
			2025						2024						2023						2025						2024						2023
Weighted-average Assumptions to Determine Net Periodic Benefit Cost
Discount rate - service cost			5.74		%				5.06		%				5.25		%				5.89		%				5.14		%				5.30		%
Discount rate - interest cost			5.28		%				4.88		%				5.06		%				5.35		%				4.89		%				5.07		%
Expected long-term rate of return on plan assets			7.30		%				7.02		%				7.00		%				7.09		%				7.06		%				6.96		%
Rate of compensation increases			4.00		%				4.00		%				4.00		%				N/A						N/A						N/A
Interest crediting rates			4.00		%				4.00		%				4.00		%				N/A						N/A						N/A

We assumed a 7.30% and 7.09% rate of return on pension and other postretirement plan assets, respectively, for our calculation of 2025 pension benefits and other postretirement benefits costs. These rates were primarily based on asset mix and historical rates of return and were adjusted in 2025 due to changes in asset allocation and projected market returns.

The following table provides other changes in plan assets and projected benefit obligations recognized in other comprehensive income or regulatory asset or liability:

			Pension Benefits												Other Postretirement Benefits
(in millions)			2025						2024						2025						2024
Other Changes in Plan Assets and Projected Benefit Obligations Recognized in Other Comprehensive Income or Regulatory Asset or Liability
Net prior service (credit) cost			$	—					$	—					$	(30.3)					$	—
Net actuarial (gain) loss			(5.6)						(13.1)						(13.7)						(26.4)
One time charge			(6.5)						(7.2)						(3.4)						—
Less: amortization of prior service cost			(0.1)						(0.1)						2.6						1.8
Less: amortization of net actuarial loss			(25.5)						(28.6)						(1.7)						(3.2)
Total Recognized in Other Comprehensive Income or Regulatory Asset or Liability			$	(37.7)					$	(49.0)					$	(46.5)					$	(27.8)
Amount Recognized in Net Periodic Benefits Cost and Other Comprehensive Income or Regulatory Asset or Liability			$	(14.2)					$	(21.6)					$	(35.1)					$	(15.5)

In August 2025, we communicated to plan participants of one of our OPEB plans the intention to move from a group self insured Medicare supplemental health plan to a Sponsored Health Reimbursement Account, with eligible retirees electing coverage through a Healthcare Exchange, effective on January 1, 2026. Given the intention of the plan and communication to participants, this was considered a plan amendment at the time of communication. This plan amendment triggered remeasurement of this plan, resulting in a decrease to the OPEB regulatory asset of $5.7 million, a decrease to OPEB liability of $23.3 million, and an increase to accumulated other comprehensive loss of $17.6 million. Net periodic OPEB benefit cost for 2025 decreased by $1.7 million as a result of the interim remeasurement. Additionally, this change resulted in the Net prior service (credit) cost of $30.3 million in the table above.

In line with the remeasurement, key inputs, economic assumptions, and demographic assumptions changed to calculate the updated OPEB benefit obligation and the net periodic benefit cost at the interim remeasurement date for the plan that triggered settlement accounting. For remeasurement, we used a weighted-average discount rate of 5.53%, a weighted-average health care trend rate of 9.97% for next year and ultimate trend rate of 4.75% to be reached in 2034, and weighted-average expected return on assets of 6.88%.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

17. Share-Based Compensation

Prior to May 19, 2020, we issued share-based compensation to employees and non-employee directors under the NiSource Inc. 2010 Omnibus Plan ("2010 Omnibus Plan"), which was most recently approved by stockholders at the Annual Meeting of Stockholders held on May 12, 2015. The 2010 Omnibus Plan provided for awards to employees and non-employee directors of incentive and nonqualified stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, cash-based awards and other stock-based awards and superseded the Director Stock Incentive Plan (“Director Plan”) with respect to grants made after the effective date of the 2010 Omnibus Plan.

The stockholders approved and adopted the NiSource Inc. 2020 Omnibus Incentive Plan ("2020 Omnibus Plan") at the Annual Meeting of Stockholders held on May 19, 2020. The 2020 Omnibus Plan provides for awards to employees and non-employee directors of incentive and nonqualified stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance units, cash-based awards and other stock-based awards and supersedes the 2010 Omnibus Plan with respect to grants made after the effective date of the 2020 Omnibus Plan.

The 2020 Omnibus Plan provides that the number of shares of common stock of NiSource available for awards is 10,000,000 plus the number of shares subject to outstanding awards that expire or terminate for any reason that were granted under the 2020 Omnibus Plan, the 2010 Omnibus Plan or any other equity plan under which awards were outstanding as of May 19, 2020. At December 31, 2025, there were 6,537,216 shares available for future awards under the 2020 Omnibus Plan.

We recognized stock-based employee compensation expense of $40.9 million, $32.1 million and $23.9 million, during 2025, 2024 and 2023, respectively, as well as capitalized stock-based compensation cost of $5.1 million, $4.1 million, and zero during the same periods. We recognized related tax benefits of $11.1 million, $7.0 million and $7.7 million, during 2025, 2024 and 2023, respectively. We recognized related excess tax benefits from the distribution of vested share-based employee compensation of $5.1 million, $2.0 million, and $2.9 million in 2025, 2024 and 2023, respectively.

As of December 31, 2025, the total remaining unrecognized compensation cost related to non-vested awards amounted to $59.2 million, which will be amortized over the weighted-average remaining requisite service period of 1.8 years.

Restricted Stock Units and Restricted Stock. We granted 550,614, 655,713, and 500,968 restricted stock units and shares of restricted stock to employees, subject to service conditions in 2025, 2024, and 2023, respectively. The total grant date fair value of the restricted stock units and shares of restricted stock during 2025, 2024, and 2023, respectively, was $21.2 million, $17.1 million, and $13.7 million. The grant date fair value for the 2025, 2024 and 2023 awards is based on the average market price of our common stock at the date of each grant. The awards are expensed over the vesting period which is generally three years. As of December 31, 2025, 521,157, 508,444, and 316,439 non-vested restricted stock units and shares of restricted stock granted in 2025, 2024, and 2023, respectively, were outstanding. Our non-vested restricted stock units have a non-forfeitable right to dividend equivalents, with immaterial amounts paid in the periods ending December 31, 2025 and 2023. See Note 5, "Earnings Per Share," for further discussion.

In general, if an employee terminates employment before the service conditions lapse under the 2023, 2024 or 2025 awards due to (i) retirement or disability (as defined in the 2020 Omnibus Plan), or (ii) death, the service conditions will lapse on the date of such termination with respect to a pro rata portion of the restricted stock units and shares of restricted stock based upon the percentage of the service period satisfied between the grant date and the date of the termination of employment. In the event of a change in control (as defined in the 2020 Omnibus Plan), all unvested shares of restricted stock and restricted stock units awarded will immediately vest upon termination of employment occurring in connection with a change in control. Termination due to any other reason, in general, will result in all unvested shares of restricted stock and restricted stock units awarded being forfeited effective on the employee’s date of termination.

A summary of our restricted stock unit award transactions for the year ended December 31, 2025 is as follows:

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

(shares)			Restricted Stock Units						Weighted Average Award Date Fair Value Per Unit ($)
Non-vested at December 31, 2024			1,328,120						26.49
Granted			550,614						38.59
Forfeited			(92,759)						29.98
Vested			(368,139)						26.57
Non-vested at December 31, 2025			1,417,836						31.19

Employee Performance Shares. We granted 643,683 performance shares subject to service, performance and/or market-based vesting conditions in 2025. The performance conditions for these shares are based on the achievement of one non-GAAP financial measure, achievement of relative total shareholder return, and other operational metrics, which make up 50%, 30%, and 20% of the issued awards respectively.

The non-GAAP financial measure is cumulative adjusted earnings per share, which we define as diluted earnings per share adjusted for certain items. Relative total shareholder return, a market-based vesting condition, which we define as the annualized growth in dividends and share price of a share of our common stock (calculated using a 20 trading day average of our closing price over the performance period, approximately) compared to the total shareholder return of a predetermined peer group of companies. A Monte Carlo analysis was used to value the portion of these awards dependent on the market-based vesting condition. The grant date fair value of the non-GAAP financial measure shares is based on the closing stock price of our common stock at the date of each grant, which will be expensed over the requisite service period of three years. The conditions for the remaining performance-based awards are based on operational goals of Annual Operational Index Scorecard (10%), Employee Engagement Index Score (5%), and Environmental Greenhouse Gas Reduction (5%).

In 2024, we granted 896,363 performance shares subject to service, performance and/or market-based vesting conditions. The performance conditions for these shares are based on the achievement of one non-GAAP financial measure, achievement of relative total shareholder return, and other operational metrics, which make up 55%, 25%, and 20% of the issued awards respectively. The conditions for the remaining performance-based awards are based on operational goals of Annual Operational Index Scorecard (10%), Employee Engagement Index Score (5%), and Environmental Greenhouse Gas Reduction (5%).

In 2023, we granted 649,088 performance shares subject to service, performance and/or market-based vesting conditions. The performance conditions for these shares are based on the achievement of one non-GAAP financial measure, achievement of relative total shareholder return, and other operational metrics, which make up 50%, 25%, and 25% of the issued awards respectively. The operational metrics consist of goals of economic inclusion (5%), OPEX ("Operating Expenses") Index (10%), Employee Engagement Index Score (5%), and Environmental GHG Reduction (5%). The OPEX Index is further defined by goals related to risk mitigation and modernization of our infrastructure.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

The following table presents details of the performance awards described above.

Award Year			Service Conditions Lapse date			Performance Period			Award Conditions						Shares outstanding at 12/31/2025 (shares)			Grant Date Fair Value (in millions)
2025			2/29/2028			01/01/2025- 12/31/2027			Non-GAAP Financial and Operational Measures						449,007			$	11.5
Relative Total Shareholder Return						190,095			$	4.7
2024			2/26/2027			01/01/2024- 12/31/2026			Non-GAAP Financial and Operational Measures						610,945			$	15.7
Relative Total Shareholder Return						203,614			$	6.2
2023			2/28/2026			01/01/2023- 12/31/2025			Non-GAAP Financial and Operational Measures						421,980			$	17.1
Relative Total Shareholder Return						140,647			$	9.3

A summary of our performance award transactions for the year ended December 31, 2025 is as follows:

(shares)			Performance Awards						Weighted Average Grant Date Fair Value Per Unit ($)
Non-vested at December 31, 2024			1,719,223						24.96
Granted			643,683						41.26
Forfeited			(83,879)						31.36
Vested			(334,843)						32.91
Non-vested at December 31, 2025			1,944,184						18.93

Non-employee Director Awards. As of May 19, 2020, awards to non-employee directors may be made only under the 2020 Omnibus Plan. Currently, restricted stock units are granted annually to non-employee directors, subject to a non-employee director’s election to defer receipt of such restricted stock unit award. The non-employee director’s annual award of restricted stock units vest on the first anniversary of the grant date subject to special pro-rata vesting rules in the event of retirement or disability (as defined in the award agreement), or death. The vested restricted stock units are payable as soon as practicable following vesting except as otherwise provided pursuant to the non-employee director’s deferral election. Certain restricted stock units remain outstanding from the 2010 Omnibus Plan and the Director Plan. All such awards are fully vested and shall be distributed to the directors upon their separation from the Board.

As of December 31, 2025, 292,441 restricted stock units are outstanding to non-employee directors under either the 2020 Omnibus Plan, the 2010 Omnibus Plan or the Director Plan. Of this amount, 50,612 restricted stock units are unvested and expected to vest.

401(k) Match, Profit Sharing and Company Contribution. Eligible salaried employees hired after January 1, 2010 and hourly and union employees hired after January 1, 2013 receive a non-elective company contribution of 4.5% of eligible pay payable in cash or shares of NiSource common stock. We also have a voluntary 401(k) savings plan covering eligible union and nonunion employees that allows for periodic discretionary matches as a percentage of each participant’s contributions payable in cash or shares. Further, we have a retirement savings plan that provides for discretionary profit sharing contributions to eligible employees. For the years ended December 31, 2025, 2024 and 2023, we recognized 401(k) match, profit sharing and non-elective contribution expense of $59.0 million, $56.9 million and $50.7 million, respectively.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

18. Leases

Lease Descriptions. We are the lessee for substantially all of our leasing activity, which includes operating and finance leases for corporate and field offices, railcars, land, and fleet vehicles. Our corporate and field office leases and certain land leases have remaining terms between 1 and 38 years with options to renew the leases for up to 35 years. We lease railcars to transport coal to and from our electric generation facilities in Indiana. Our railcars are specifically identified in the lease agreements which have remaining lease terms between 1 and 3 years with options to renew for 1 year. Our fleet vehicles include trucks, trailers and equipment that have been customized specifically for use in the utility industry. We lease fleet vehicles for 1 year terms, after which we have the option to extend on a month-to-month basis or terminate with written notice. We elected the short-term lease practical expedient, allowing us to not recognize ROU assets or lease liabilities for all leases with a term of 12 months or less. ROU assets and liabilities on our Consolidated Balance Sheets do not include obligations for possible fleet vehicle lease renewals beyond the initial lease term. While we have the ability to renew these leases beyond the initial term, we are not reasonably certain to do so.

We have not provided material residual value guarantees for our leases, nor do our leases contain material restrictions or covenants. Lease contracts containing renewal and termination options are mostly exercisable at our sole discretion. Certain of our real estate and railcar leases include renewal periods in the measurement of the lease obligation if we have deemed the renewals reasonably certain to be exercised.

With respect to service contracts involving the use of assets, if we have the right to direct the use of the asset and obtain substantially all economic benefits from the use of an asset, we account for the service contract as a lease. Unless specifically provided to us by the lessor, we utilize NiSource's collateralized incremental borrowing rate commensurate to the lease term as the discount rate for all of our leases. ASC 842 permits a lessee, by class of underlying asset, not to separate nonlease components from lease components. Our policy is to apply this expedient for our leases of fleet vehicles, IT assets and railcars when calculating their respective lease liabilities.

Lease costs for the years ended December 31, 2025 and December 31, 2024 are presented in the table below. These costs include both amounts recognized in expense and amounts capitalized as part of the cost of another asset. Income statement presentation for these costs (when ultimately recognized on the income statement) is also included:

Year Ended December 31, (in millions)			Income Statement Classification			2025						2024
Finance lease cost
Amortization of right-of-use assets			Depreciation and amortization			$	20.5					$	27.1
Interest on lease liabilities			Interest expense, net			12.9						13.5
Total finance lease cost						33.4						40.6
Operating lease cost			Operation and maintenance			14.3						14.7
Total lease cost						$	47.7					$	55.3

Our right-of-use assets and liabilities are presented in the following lines on the Consolidated Balance Sheets:

At December 31, (in millions)			Balance Sheet Classification			2025						2024
Assets
Finance leases			Net Property, Plant and Equipment			$	249.8					$	222.9
Operating leases			Deferred charges and other			25.8						26.4
Total leased assets						$	275.6					$	249.3
Liabilities
Current
Finance leases			Current portion of long-term debt			$	19.7					$	22.9
Operating leases			Other accruals			9.7						9.1
Noncurrent
Finance leases			Long-term debt, excluding amounts due within one year			254.3						223.3
Operating leases			Other noncurrent liabilities and deferred credits			17.2						18.2
Total lease liabilities						$	300.9					$	273.5

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Other pertinent information related to leases was as follows:

Year Ended December 31, (in millions)			2025						2024
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows used for finance leases			$	14.5					$	11.2
Operating cash flows used for operating leases			15.7						14.5
Financing cash flows used for finance leases			22.0						26.9
Right-of-use assets obtained in exchange for lease obligations
Finance leases			50.2						65.9
Operating leases			$	13.9					$	12.2

			December 31, 2025						December 31, 2024
Weighted-average remaining lease term (years)
Finance leases			21.8						20.5
Operating leases			5.3						5.6
Weighted-average discount rate
Finance leases			5.7		%				5.6		%
Operating leases			4.5		%				4.5		%

Maturities of our lease liabilities as of December 31, 2025 were as follows:

As of December 31, 2025, (in millions)			Total			Finance Leases			Operating Leases
2026			$	43.3		$	32.6		$	10.7
2027			32.5			27.4			5.1
2028			30.0			26.2			3.8
2029			24.5			21.3			3.2
2030			24.4			22.3			2.1
Thereafter			373.7			368.1			5.6
Total lease payments			528.4			497.9			30.5
Less: Imputed interest			(227.5)			(223.9)			(3.6)
Total			$	300.9		$	274.0		$	26.9
Reported as of December 31, 2025
Short-term lease liabilities			29.4			19.7			9.7
Long-term lease liabilities			271.5			254.3			17.2
Total lease liabilities			$	300.9		$	274.0		$	26.9

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

19. Other Commitments and Contingencies

A. Contractual Obligations. We have certain contractual obligations requiring payments at specified periods. The obligations include long-term debt, lease obligations, energy commodity contracts and obligations for various services including pipeline capacity and outsourcing of IT services. The total contractual obligations in existence at December 31, 2025 and their maturities were:

(in millions)			Total						2026						2027						2028						2029						2030						After
Long-term debt (1)			$	15,345.0					$	—					$	1,090.0					$	1,055.0					$	1,350.0					$	1,000.0					$	10,850.0
Interest payments on long-term debt			12,361.2						729.1						725.1						675.0						647.3						575.9						9,008.8
Finance leases(2)			497.9						32.6						27.4						26.2						21.3						22.3						368.1
Operating leases(3)			30.5						10.7						5.1						3.8						3.2						2.1						5.6
Energy commodity and capacity contracts			476.9						315.9						116.7						9.3						7.6						4.6						22.8
Service obligations:
Pipeline service obligations			2,829.1						809.5						879.3						482.3						326.5						156.6						174.9
IT service obligations			322.1						98.3						81.8						61.7						43.0						37.3						—
Plant equipment purchase obligations			103.3						87.6						10.4						5.3						—						—						—
Other liabilities(4)			120.3						74.0						10.1						9.5						8.4						8.0						10.3
Total contractual obligations			$	32,086.3					$	2,157.7					$	2,945.9					$	2,328.1					$	2,407.3					$	1,806.8					$	20,440.5

(1) Long-term debt balance excludes unamortized issuance costs and discounts of $141.5 million and finance leases of $274.0 million.

(2) Finance lease payments shown above are inclusive of interest totaling $223.9 million.

(3) Operating lease payments shown above are inclusive of interest totaling $3.6 million. Operating lease balances do not include obligations for possible fleet vehicle lease renewals beyond the initial lease term. While we have the ability to renew these leases beyond the initial term, we are not reasonably certain to do so as they are renewed month-to-month after the first year.

(4)Other liabilities shown above are primarily related to the current EPC contract and ongoing maintenance service agreements for our renewable joint ventures.

Purchase and Service Obligations. We have entered into various purchase and service agreements whereby we are contractually obligated to make certain minimum payments in future periods. Our energy commodity contracts are for the purchase of physical quantities of natural gas, electricity, coal and purchases of electric capacity. Our service obligations, consisting of pipeline service obligations and IT service obligations, encompass a broad range of business support and maintenance functions which are generally described below. Our plant equipment purchase obligations are for plant equipment, typically for generation assets, with long lead times that require payments made over time.

Our subsidiaries have entered into various energy commodity contracts to purchase physical quantities of natural gas, electricity, coal and purchases of electric capacity. These amounts represent the minimum quantity of these commodities we are obligated to purchase at both fixed and variable prices. To the extent contractual purchase prices are variable, obligations disclosed in the table above are valued at market prices as of December 31, 2025.

NIPSCO has PPAs representing approximately 1,200 MW of capacity, with contracts expiring between 2038 and 2045. No minimum quantities are specified within these agreements due to the variability of electricity generation, so no amounts related to these contracts are included in the table above. Upon early termination of one of these agreements by NIPSCO for any reason (other than material breach by the counterparties), NIPSCO may be required to pay a termination charge that could be material depending on the events giving rise to termination and the timing of the termination.

We have pipeline service agreements that provide for pipeline capacity, transportation and storage services. These agreements, which have expiration dates ranging from 2030 to 2044, require us to pay fixed monthly charges.

NIPSCO has contracts with three rail operators providing coal transportation services for which there are certain minimum payments. These service contracts extend for various periods from 2026 through 2028.

We have executed agreements with multiple IT service providers. The agreements extend for various periods through 2030.

B. Guarantees and Indemnities. We and certain of our subsidiaries enter into various agreements providing financial or performance assurance to third parties on behalf of certain subsidiaries as part of normal business. Such agreements include guarantees and stand-by letters of credit. These agreements are entered into primarily to support or enhance the creditworthiness otherwise attributed to a subsidiary on a stand-alone basis, thereby facilitating the extension of sufficient credit to accomplish

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

the subsidiaries’ intended commercial purposes. At December 31, 2025 and 2024, we issued letters of credit of $119.0 million and $9.4 million, respectively, for the benefit of third parties.

We provide guarantees related to our future performance under BTAs for our renewable generation projects. At December 31, 2025 and 2024, our guarantees for multiple BTAs totaled $27.2 million and $1,127.5 million, respectively. The amount of each guaranty will decrease upon the substantial completion of the construction of the facilities. See “- E. Other Matters - Generation Transition,” below for more information.

We provide guarantees related to some of our rail and pipeline service agreements. If we do not meet our contractual obligations under the terms of these agreements we would be required to pay up to a maximum of $52.0 million.

C. Legal Proceedings. From time to time, various legal and regulatory claims and proceedings are pending or threatened against the Company and its subsidiaries. While the amounts claimed may be substantial, the Company is unable to predict with certainty the ultimate outcome of such claims and proceedings. The Company establishes reserves whenever it believes it to be appropriate for pending litigation matters. However, the actual results of resolving the pending litigation matters may be substantially higher than the amounts reserved. If one or more other matters were decided against us, the effects could be material to our results of operations in the period in which we would be required to record or adjust the related liability and could also be material to our cash flows in the periods that we would be required to pay such liability. Due to the inherent uncertainty of litigation, there can be no assurance that the resolution of any particular claim, proceeding or investigation would not have a material adverse effect on our results of operations, financial position or liquidity.

Other Claims and Proceedings. We are also party to certain other claims, regulatory and legal proceedings arising in the ordinary course of business in each state in which we have operations, and based upon an investigation of these matters and discussion with legal counsel, we believe the ultimate outcome of such other legal proceedings to be individually, or in aggregate, not material at this time.

D. Environmental Matters. Our operations are subject to environmental statutes and regulations related to air quality, water quality, hazardous waste and solid waste. We believe that we are in substantial compliance with the environmental regulations currently applicable to our operations.

It is management's continued intent to address environmental issues in cooperation with regulatory authorities in such a manner as to achieve mutually acceptable compliance plans. However, there can be no assurance that fines and penalties will not be incurred. Management expects the majority of environmental assessment and remediation costs and asset retirement costs, further described below, to be recoverable through rates. See Note 11, "Asset Retirement Obligations" and Note 12, "Regulatory Matters," for additional detail.

As of December 31, 2025 and 2024, we had recorded a liability of $82.6 million and $91.8 million, respectively, to cover environmental remediation at various sites. This liability is included in "Other accruals" and "Other noncurrent liabilities and deferred credits" in the Consolidated Balance Sheets. We recognize costs associated with environmental remediation obligations when the incurrence of such costs is probable and the amounts can be reasonably estimated. The original estimates for remediation activities may differ materially from the amount ultimately expended. The actual future expenditures depend on many factors, including laws and regulations, the nature and extent of impact and the method of remediation. These expenditures are not currently estimable at some sites. We periodically adjust our liability as information is collected and estimates become more refined.

CERCLA. Our subsidiaries are potentially responsible parties at waste disposal sites under the CERCLA and similar state laws. Under CERCLA, each potentially responsible party can be held jointly, severally and strictly liable for the remediation costs as the EPA, or state, can allow the parties to pay for remedial action or perform remedial action themselves and request reimbursement from the potentially responsible parties. Our affiliates have retained CERCLA environmental liabilities, including remediation liabilities, associated with certain current and former operations. At this time, we cannot estimate the full cost of remediating properties that have not yet been investigated, but it is possible that the future costs could be material to the Consolidated Financial Statements.

MGP. We maintain a program to identify and investigate former MGP sites where gas distribution subsidiaries or predecessors may have liability. The program has identified 41 such sites where liability is probable. Remedial actions at many of these sites are being overseen by state or federal environmental agencies through consent agreements or voluntary remediation agreements.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

We utilize a probabilistic model to estimate our future remediation costs related to MGP sites. The model was prepared with the assistance of a third party and incorporates our experience and general industry experience with remediating MGP sites. We complete an annual refresh of the model in the second quarter of each fiscal year. No material changes to the estimated future remediation costs were identified during the update completed as of June 30, 2025. Our total estimated liability related to the facilities subject to remediation was $75.5 million and $86.4 million at December 31, 2025 and 2024, respectively. The liability represents our best estimate of the probable cost to remediate the MGP sites. Our model indicates that it is reasonably possible that remediation costs could vary by as much as $16.5 million in addition to the costs noted above. Remediation costs are estimated based on the best available information, applicable remediation standards at the balance sheet date, and experience with similar facilities.

CCRs. NIPSCO continues to meet the compliance requirements established by the EPA for the regulation of CCRs. The CCR rule requirements currently in effect required revisions to previously recorded legal obligations associated with the retirement of certain NIPSCO facilities. The actual asset retirement costs related to the CCR rule may vary substantially from the estimates used to record the increased asset retirement obligation due to the uncertainty about the requirements that will be established by environmental authorities, compliance strategies that will be used and the preliminary nature of available data used to estimate costs. As allowed by the rule, NIPSCO will continue to collect data over time to determine the specific compliance solutions and associated costs and, as a result, the actual costs may vary.

On May 8, 2024, the EPA finalized changes to the current CCR regulations ("Legacy CCR Rule") which address inactive surface impoundments at inactive facilities, referred to as legacy impoundments, and CCR management units ("CCRMUs") at inactive and active facilities. The rule largely requires these newly regulated units to conform to existing requirements, such as groundwater monitoring, closure requirements, and post-closure care. During 2025, we accrued an additional $48.9 million to cover probable and estimable compliance activities associated with the Legacy CCR Rule. NIPSCO continues to assess whether existing legal obligations associated with the retirement of certain facilities must be revised and to estimate probable additional required asset retirement costs. NIPSCO expects to receive recovery of any such costs through existing and future depreciation rates.

E. Other Matters

Generation Transition. In October 2024, NIPSCO contracted with a developer to convert the previously approved Templeton PPA to a BTA and in February 2025 filed a CPCN with the IURC seeking approval of the full ownership BTA structure. In September 2025, the IURC granted NIPSCO a CPCN to acquire Templeton through the full ownership BTA structure. NIPSCO's purchase obligation under Templeton is dependent on timely completion of construction. Certain agreements require NIPSCO to make partial payments upon the developer's completion of significant construction milestones.

In January 2025, the Fairbanks project achieved mechanical completion, resulting in NIPSCO making a $336.6 million payment to the developer. In May 2025, the Fairbanks project achieved substantial completion, resulting in NIPSCO making a $141.4 million payment to the developer in June 2025. In December 2025, the Fairbanks project achieved final completion, resulting in NIPSCO making a $3.6 million payment to the developer.

In January 2025, the Dunns Bridge II project achieved substantial completion, resulting in NIPSCO making a $217.6 million payment to the developer in February 2025. In October 2025, the Dunns Bridge II project achieved final completion resulting in a NIPSCO making a $4.2 million payment to the developer.

In June 2025, the Gibson project achieved mechanical completion, resulting in NIPSCO making a $262.4 million payment to the developer. In August 2025, the Gibson project achieved substantial completion, resulting in NIPSCO making a $133.7 million payment to the developer in September 2025.

NIPSCO Minority Interest Transaction. In December 2023, pursuant to the terms of the BIP Purchase Agreement and simultaneously with the closing of the NIPSCO Minority Interest Transaction, Blackstone, NIPSCO Holdings I, NIPSCO Holdings II and NiSource entered into an Amended and Restated Limited Liability Company Agreement of NIPSCO Holdings II. In January 2024, BIP transferred a 4.5% portion of its equity interest to one of its affiliates and the members of NIPSCO Holdings II entered into a Second Amended and Restated Limited Liability Company Operating Agreement of NIPSCO Holdings II. In October 2025, the members of NIPSCO Holdings II entered into a Third Amended and Restated LLC Agreement of NIPSCO Holdings II(the "Amended LLC Agreement"), which, among other changes, increased the amount and time period for additional mandatory capital contributions required to be contributed by the members affiliated with Blackstone by $175 million and seven years, which obligation is backed by an Equity Commitment Letter from Blackstone or an affiliate thereof, and amended certain provisions to facilitate NIPSCO Holdings II and its subsidiaries’ provision of electric service to

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

data center customers (and related activities) and their related contracts and arrangements with Generation Holdings II and its subsidiaries. The members of NIPSCO Holdings II that are affiliates of Blackstone must vote their equity holdings under the Amended LLC Agreement as one investor. Refer to Note 4, "Noncontrolling Interests," in the Notes to the Consolidated Financial Statements for more information on this transition.

GenCo Minority Interest Transaction. In October 2025, NiSource issued a 19.9% indirect equity interest in NiSource’s wholly-owned subsidiary GenCo to BIP Orion Holdco L.P. and BIP Orion Holdco II L.P., affiliates of Blackstone (collectively, “Blackstone Investor”), in exchange for $35.2 million in cash contributions to Generation Holdings II through the Generation Holdings II LLC Agreement. We analyzed the Generation Holdings II LLC Agreement and determined that we maintain the decision-making activities over Generation Holdings II and its wholly owned subsidiary GenCo, making Generation Holdings II a consolidated VIE. Generation Holding II is considered a VIE as it passes the variability of its operating results through to its shareholders (Generation Holdings I and Blackstone Investor) and has insufficient equity to finance its activities without additional subordinated financial support.

Refer to Note 4, "Noncontrolling Interest," for detailed discussion of accounting for the GenCo Minority Interest Transaction.

The foregoing descriptions of the Generation Holdings II LLC Agreement and the Amended LLC Agreement do not purport to be complete and are qualified in their entirety by reference to the terms and conditions of the Generation Holdings II LLC Agreement and Amended LLC Agreement, which are filed as Exhibits 10.17 and 10.16, respectively, and are incorporated by reference herein.

EPC Agreements. GenCo has entered into certain EPC contracts to construct generation capacity assets to support the ADS Contract, requiring payments at specified periods. The assets contemplated by these contracts are subject to IURC approval. We may terminate for convenience the EPC Contracts and pay certain incurred project costs and termination fees if the ADS Contract is terminated or IURC approval of the underlying assets is not obtained. Amounts that will be owed in the event of termination are included in the table above.

20. Accumulated Other Comprehensive Loss

The following table displays the activity of Accumulated Other Comprehensive Loss, net of tax:

(in millions)			Gains and Losses on Securities**(1)**						Gains and Losses on Cash Flow Hedges**(1)**						Pension and OPEB Items**(1)**						Accumulated Other Comprehensive Loss**(1)**
Balance as of December 31, 2022			$	(11.2)					$	(12.6)					$	(13.3)					$	(37.1)
Other comprehensive (loss) income before reclassifications			3.1						(0.5)						(1.4)						1.2
Amounts reclassified from accumulated other comprehensive loss			0.8						0.3						1.2						2.3
Net current-period other comprehensive (loss) income			3.9						(0.2)						(0.2)						3.5
Balance as of December 31, 2023			$	(7.3)					$	(12.8)					$	(13.5)					$	(33.6)
Other comprehensive (loss) income before reclassifications			1.5						—						(1.2)						0.3
Amounts reclassified from accumulated other comprehensive loss			1.8						(0.4)						1.5						2.9
Net current-period other comprehensive (loss) income			3.3						(0.4)						0.3						3.2
Balance as of December 31, 2024			$	(4.0)					$	(13.2)					$	(13.2)					$	(30.4)
Other comprehensive income before reclassifications			5.0						—						19.5						24.5
Amounts reclassified from accumulated other comprehensive loss			(0.9)						(0.4)						1.0						(0.3)
Net current-period other comprehensive income (loss)			4.1						(0.4)						20.5						24.2
Balance as of December 31, 2025			$	0.1					$	(13.6)					$	7.3					$	(6.2)

(1)All amounts are net of tax. Amounts in parentheses indicate debits.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

21. Business Segment Information

Our reportable segments reflect the manner in which our business is managed and our resources are allocated. Following the consummation of the NIPSCO Minority Interest Transaction, we revised how we evaluate results and allocate resources across our business with an increased focus on operating performance at the state level. Refer to Note 4, "Noncontrolling Interests," for additional information on the NIPSCO Minority Interest Transaction. At December 31, 2025, our operations are divided into two primary reportable segments, the Columbia Operations and the NIPSCO Operations segments. Columbia Operations aggregates the results of the fully regulated and wholly owned subsidiaries of NiSource Gas Distribution Group, Inc. (a holding company that owns Columbia of Kentucky, Columbia of Maryland, Columbia of Ohio, Columbia of Pennsylvania, and Columbia of Virginia). Each Columbia distribution company is an operating segment which we aggregate to form the Columbia Operations reportable segment. NIPSCO Operations includes the results of NIPSCO Holdings I and its majority-owned subsidiaries, including NIPSCO, which has fully regulated gas and electric operations in northern Indiana. Our historical segment disclosures have been recast to be consistent with the current presentation.

The remainder of our operations, which are not significant enough on a stand-alone basis to warrant treatment as an operating segment, are presented as "Corporate and Other" in the subsequent reconciliation table and primarily are comprised of interest expense on holding company debt and unallocated corporate costs and activities, as well as new business development costs associated with GenCo. Refer to Note 3, "Revenue Recognition," for additional information on our segments and their sources of revenues. The following table provides information about our reportable segments. We use operating income as our primary measurement for each of the reported segments and make decisions on financing, dividends and taxes at the corporate level on a consolidated basis. We provide this measure to our Chief Operating Decision Maker, the CEO, who utilizes this measure to make operating segment level strategy decisions based on budget-to-actual variances and against prior periods to allocate resources accordingly. Segment revenues include intersegment sales to affiliated subsidiaries, which are eliminated in consolidation. Affiliated sales are recognized on the basis of prevailing market, regulated prices or at levels provided for under contractual agreements. Operating income is derived from revenues and expenses directly associated with each segment.

Year Ended December 31, 2025 (in millions)
			Columbia Operations						NIPSCO Operations						Total of Reportable Segments
Operating Revenues
External revenue			$	3,330.0					$	3,307.4					$	6,637.4
Intersegment revenue			13.3						1.1						14.4
Total Operating Revenue			$	3,343.3					$	3,308.5					$	6,651.8
Cost of energy			819.8						764.7						1,584.5
O&M			923.7						848.9						1,772.6
Depreciation			451.2						680.6						1,131.8
Total other taxes			253.2						75.5						328.7
Other segment items(1)			0.3						0.7						1.0
Operating Income			$	895.1					$	938.1					$	1,833.2
Capital Expenditures**(2)**			$	1,213.0					$	2,508.9					$	3,721.9
Assets			$	15,903.7					$	18,126.7					$	34,030.4

(1)Other segment items consists of Loss (gain) on Sale or Impairment of Assets and other segment income or expenses deemed insignificant which are used to reach our measurement of segment profit or loss, Operating Income.

(2)Amounts differ from those presented on the Statements of Consolidated Cash Flows primarily due to the inclusion of capital expenditures in current liabilities, the capitalized portion of the Corporate Incentive Plan payout, and AFUDC Equity.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Year Ended December 31, 2024 (in millions)
			Columbia Operations						NIPSCO Operations						Total of Reportable Segments
Operating Revenues
External revenue			$	2,703.2					$	2,751.0					$	5,454.2
Intersegment revenue			12.8						1.0						13.8
Total Operating Revenue			$	2,716.0					$	2,752.0					$	5,468.0
Cost of energy			514.7						617.5						1,132.2
O&M			837.5						761.4						1,598.9
Depreciation			409.1						590.3						999.4
Total other taxes			218.6						64.3						282.9
Other segment items(1)			7.4						(1.3)						6.1
Operating Income			$	728.7					$	719.8					$	1,448.5
Capital Expenditures**(2)**			$	1,209.0					$	2,252.4					$	3,461.4
Assets			$	14,769.5					$	15,823.5					$	30,593.0

(1)Other segment items consists of Loss(gain) on Sale or Impairment of Assets and other segment income or expenses deemed insignificant which are used to reach our measurement of segment profit or loss, Operating Income.

(2)Amounts differ from those presented on the Statements of Consolidated Cash Flows primarily due to the inclusion of capital expenditures in current liabilities, the capitalized portion of the Corporate Incentive Plan payout, and AFUDC Equity.

Year Ended December 31, 2023 (in millions)
			Columbia Operations						NIPSCO Operations						Total of Reportable Segments
Operating Revenues
External revenue			$	2,733.9					$	2,770.7					$	5,504.6
Intersegment revenue			12.2						0.9						13.1
Total Operating Revenue			$	2,746.1					$	2,771.6					$	5,517.7
Cost of energy			645.0						888.3						1,533.3
O&M			792.3						787.7						1,580.0
Depreciation			371.7						493.8						865.5
Total other taxes			198.8						57.9						256.7
Other segment items(1)			—						2.2						2.2
Operating Income			$	738.3					$	541.7					$	1,280.0
Capital Expenditures**(2)**			$	1,159.6					$	1,294.8					$	2,454.4
Assets			$	13,664.5					$	13,962.6					$	27,627.1

(1)Other segment items consists of proceeds from a property insurance settlement related to the Greater Lawrence Incident and other segment income or expenses deemed insignificant which are used to reach our measurement of segment profit or loss, Operating Income.

(2)Amounts differ from those presented on the Statements of Consolidated Cash Flows primarily due to the inclusion of capital expenditures in current liabilities, the capitalized portion of the Corporate Incentive Plan payout, and AFUDC Equity.

To reconcile the segment tables above to consolidated NiSource:

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

Year Ended December 31, 2025 (in millions)
			Total Reportable Segments						Corporate and Other						Eliminations			Consolidated NiSource
Total Operating Revenue			$	6,651.8					$	600.1					$	(609.7)		$	6,642.2
Operating Income			1,833.2						2.1						—			1,835.3
Capital Expenditures			3,721.9						329.7						—			4,051.6
Assets			34,030.4						1,828.3						—			35,858.7
Year Ended December 31, 2024 (in millions)
			Total Reportable Segments						Corporate and Other						Eliminations			Consolidated NiSource
Total Operating Revenue			$	5,468.0					$	581.9					$	(594.8)		$	5,455.1
Operating Income			1,448.5						7.0						—			1,455.5
Capital Expenditures			3,461.4						231.1						—			3,692.5
Assets			30,593.0						1,195.1						—			31,788.1
Year Ended December 31, 2023 (in millions)
			Total Reportable Segments						Corporate and Other						Eliminations			Consolidated NiSource
Total Operating Revenue			$	5,517.7					$	504.6					$	(516.9)		$	5,505.4
Operating Income			1,280.0						15.5						—			1,295.5
Capital Expenditures			2,454.4						236.3						—			2,690.7
Assets			27,627.1						3,450.1						—			31,077.2

22. Other, Net

The following table displays the components of Other, Net included on the Statements of Consolidated Income:

Year Ended December 31, (in millions)			2025						2024						2023
Interest income			$	10.2					$	10.4					$	9.0
AFUDC equity			32.7						75.1						25.2
Charitable contributions			(4.8)						(5.4)						(1.8)
Pension and other postretirement non-service cost(1)			(13.0)						(13.5)						(24.0)
Tax penalty			(4.0)						(0.7)						—
Heating assistance			(2.1)						(0.5)						(0.8)
Miscellaneous			1.1						(0.9)						0.4
Total Other, net			$	20.1					$	64.5					$	8.0

(1) See Note 16, "Pension and Other Postemployment Benefits," for additional information.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued) Notes to Consolidated Financial Statements

23. Interest Expense, Net

The following table displays the components of Interest Expense, Net included on the Statements of Consolidated Income:

Year Ended December 31, (in millions)			2025						2024						2023
Interest on long-term debt			$	647.8					$	506.2					$	404.1
Interest on short-term borrowings			36.7						43.2						108.9
Debt discount/cost amortization			15.2						13.8						13.5
Accounts receivable securitization fees			1.4						1.5						2.7
Allowance for borrowed funds used and interest capitalized during construction			(37.8)						(40.1)						(25.3)
Debt-based post-in-service carrying charges			(47.4)						(26.4)						(30.7)
Other			23.1						19.0						16.4
Total Interest Expense, net			$	639.0					$	517.2					$	489.6

24. Supplemental Cash Flow Information

The following table provides additional information regarding our Consolidated Statements of Cash Flows for the years ended December 31, 2025, 2024 and 2023:

Year Ended December 31, (in millions)			2025						2024						2023
Supplemental Disclosures of Cash Flow Information
Non-cash transactions:
Capital expenditures included in current liabilities			$	479.9					$	367.0					$	315.0
Assets acquired under a finance lease			50.2						65.9						64.5
Assets acquired under an operating lease			13.9						12.2						5.6
Assets recorded for asset retirement obligations(1)			88.7						277.4						61.1
Schedule of interest and income taxes paid:
Cash paid for interest on debt, net of interest capitalized amounts			$	557.1					$	468.2					$	433.9
Cash paid for interest on finance leases			14.5						11.2						8.6
Cash paid for income taxes, net of refunds			3.3						4.3						9.4

(1)See Note 11, "Asset Retirement Obligations," for additional information.

NIS****OURCE INC.

ITEM 8. FINANCIAL STATEMENTS AND SUPPLEMENTARY DATA (continued)

NISOURCE INC.

SCHEDULE II – VALUATION AND QUALIFYING ACCOUNTS

Twelve months ended December 31, 2025
									Additions
($ in millions)			Balance Jan. 1, 2025						Charged to Costs and Expenses						Charged to Other Account (1)									Deductions for Purposes for which Reserves were Created						Balance Dec. 31, 2025
Reserves Deducted in Consolidated Balance Sheet from Assets to Which They Apply:
Reserve for accounts receivable			$	23.7					$	40.8					$	40.9								$	64.8					$	40.6
Reserve for deferred charges and other			1.1						—						0.2									—						1.3
Twelve months ended December 31, 2024
									Additions
($ in millions)			Balance Jan. 1, 2024						Charged to Costs and Expenses						Charged to Other Account (1)									Deductions for Purposes for which Reserves were Created						Balance Dec. 31, 2024
Reserves Deducted in Consolidated Balance Sheet from Assets to Which They Apply:
Reserve for accounts receivable			$	22.9					$	23.2					$	32.3								$	54.7					$	23.7
Reserve for deferred charges and other			1.3						—						(0.2)									—						1.1
Twelve months ended December 31, 2023
									Additions
($ in millions)			Balance Jan. 1, 2023						Charged to Costs and Expenses						Charged to Other Account (1)									Deductions for Purposes for which Reserves were Created						Balance Dec. 31, 2023
Reserves Deducted in Consolidated Balance Sheet from Assets to Which They Apply:
Reserve for accounts receivable			$	23.9					$	23.4					$	36.6								$	61.0					$	22.9
Reserve for deferred charges and other			1.0						—						0.3									—						1.3

(1) Charged to Other Accounts reflects the deferral of bad debt expense to a regulatory asset or the movement of the reserve between short term and long term.

NIS****OURCE INC.