Item 1. FINANCIAL STATEMENTS

NiSource Inc.

Condensed Statements of Consolidated Income (unaudited)

			Three Months Ended September 30,												Nine Months Ended September 30,
(in millions, except per share amounts)			2024						2023						2024						2023
Operating Revenues
Customer revenues			$	1,046.1					$	1,002.6					$	3,743.2					$	3,965.9
Other revenues			30.2						24.8						124.1						117.5
Total Operating Revenues			1,076.3						1,027.4						3,867.3						4,083.4
Operating Expenses
Cost of energy			165.9						181.3						755.6						1,198.3
Operation and maintenance			357.4						341.2						1,093.5						1,101.9
Depreciation and amortization			269.5						210.9						765.1						650.9
Loss on impairment of assets			—						—						2.9						—
Loss (gain) on sale of assets, net			(0.5)						(0.2)						1.1						(0.5)
Other taxes			65.7						61.2						210.4						199.9
Total Operating Expenses			858.0						794.4						2,828.6						3,150.5
Operating Income			218.3						233.0						1,038.7						932.9
Other Income (Deductions)
Interest expense, net			(134.6)						(129.2)						(380.2)						(348.6)
Other, net			29.2						(1.6)						51.4						1.9
Total Other Deductions, Net			(105.4)						(130.8)						(328.8)						(346.7)
Income before Income Taxes			112.9						102.2						709.9						586.2
Income Taxes			15.9						3.8						109.5						103.7
Net Income			97.0						98.4						600.4						482.5
Net income attributable to noncontrolling interest			11.3						13.3						63.9						5.6
Net Income Attributable to NiSource			85.7						85.1						536.5						476.9
Preferred dividends			—						(8.1)						(6.7)						(34.6)
Preferred redemption premium			—						—						(14.0)						(6.2)
Net Income Available to Common Shareholders			$	85.7					$	77.0					$	515.8					$	436.1
Earnings Per Share
Basic Earnings Per Share			$	0.19					$	0.19					$	1.15					$	1.05
Diluted Earnings Per Share			$	0.19					$	0.17					$	1.14					$	0.98
Basic Average Common Shares Outstanding			451.9						413.5						449.4						413.2
Diluted Average Common Shares			454.5						448.3						451.4						447.4

The accompanying Notes to Condensed Consolidated Financial Statements (unaudited) are an integral part of these statements.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Condensed Statements of Consolidated Comprehensive Income (unaudited)

			Three Months Ended September 30,												Nine Months Ended September 30,
(in millions, net of taxes)			2024						2023						2024						2023
Net Income			$	97.0					$	98.4					$	600.4					$	482.5
Other comprehensive income:
Net unrealized gain (loss) on available-for-sale debt securities(1)			3.5						(1.7)						3.2						(0.9)
Reclassification adjustment for cash flow hedges(2)			(0.1)						(0.1)						(0.3)						(0.2)
Unrecognized pension and OPEB benefit(3)			0.6						0.7						1.1						1.3
Total other comprehensive income (loss)			4.0						(1.1)						4.0						0.2
Comprehensive Income			$	101.0					$	97.3					$	604.4					$	482.7

(1)Net unrealized gain (loss) on available-for-sale debt securities, net of $0.9 million tax expense and $0.4 million tax benefit in the third quarter of 2024 and 2023, respectively, and $0.8 million of tax expense and $0.2 million tax benefit for the nine months ended 2024 and 2023, respectively.

(2)Reclassification adjustment for cash flow hedges, net of $0.1 million tax benefit and $0.0 million tax expense in the third quarter of 2024 and 2023, respectively, and $0.1 million of tax benefit and $0.1 million tax benefit for the nine months ended 2024 and 2023, respectively.

(3)Unrecognized pension and OPEB benefit, net of $0.2 million of tax expense and $0.3 million tax expense in the third quarter of 2024 and 2023, respectively, and $0.4 million of tax expense and $0.5 million tax expense for the nine months ended 2024 and 2023, respectively.

The accompanying Notes to Condensed Consolidated Financial Statements (unaudited) are an integral part of these statements.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Condensed Consolidated Balance Sheets (unaudited)

(in millions)			September 30, 2024						December 31, 2023
ASSETS
Property, Plant and Equipment
Plant			$	33,453.8					$	30,482.1
Accumulated depreciation and amortization			(8,572.4)						(8,207.2)
Net Property, Plant and Equipment(1)			24,881.4						22,274.9
Investments and Other Assets
Unconsolidated affiliates			6.5						5.3
Available-for-sale debt securities (amortized cost of $143.5 and $169.0, allowance for credit losses of $0.2 and $0.6, respectively)			137.9						159.1
Other investments			89.0						82.7
Total Investments and Other Assets			233.4						247.1
Current Assets
Cash and cash equivalents			126.2						2,245.4
Restricted cash			32.6						35.7
Accounts receivable			589.7						884.9
Allowance for credit losses			(17.7)						(22.9)
Accounts receivable, net			572.0						862.0
Gas storage			189.3						265.8
Materials and supplies, at average cost			167.1						172.1
Electric production fuel, at average cost			34.9						65.3
Exchange gas receivable			22.5						66.0
Regulatory assets			329.7						214.3
Deposits to renewable generation asset developer			—						454.2
Prepayments and other			141.7						118.6
Total Current Assets(1)			1,616.0						4,499.4
Other Assets
Regulatory assets			2,208.3						2,245.9
Goodwill			1,485.9						1,485.9
Deferred charges and other			403.1						324.0
Total Other Assets			4,097.3						4,055.8
Total Assets			$	30,828.1					$	31,077.2

(1)Includes $1,335.3 million and $1,369.8 million at September 30, 2024 and December 31, 2023, respectively, of net property, plant and equipment assets and $52.9 million and $63.6 million at September 30, 2024 and December 31, 2023, respectively, of current assets of consolidated VIEs that may be used only to settle obligations of the consolidated VIEs. Refer to Note 4, "Noncontrolling Interests," for additional information.

The accompanying Notes to Condensed Consolidated Financial Statements (unaudited) are an integral part of these statements.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Condensed Consolidated Balance Sheets (unaudited) (continued)

(in millions, except share amounts)			September 30, 2024						December 31, 2023
CAPITALIZATION AND LIABILITIES
Capitalization
Stockholders’ Equity
Common stock - $0.01 par value,750,000,000 shares authorized; 466,707,452 and 447,381,671 shares outstanding, respectively			$	4.7					$	4.5
Preferred stock - $0.01 par value, 20,000,000 shares authorized; 0 and 40,000 shares outstanding, respectively			—						486.1
Treasury stock			(99.9)						(99.9)
Additional paid-in capital			9,404.7						8,879.5
Retained deficit			(934.9)						(967.0)
Accumulated other comprehensive loss			(29.6)						(33.6)
Total NiSource Stockholders’ Equity			8,345.0						8,269.6
Noncontrolling interest in consolidated subsidiaries			1,983.8						1,866.7
Total Stockholders' Equity			10,328.8						10,136.3
Long-term debt, excluding amounts due within one year			12,086.3						11,055.5
Total Capitalization			22,415.1						21,191.8
Current Liabilities
Current portion of long-term debt			1,271.2						23.8
Short-term borrowings			257.0						3,048.6
Accounts payable			614.6						749.4
Dividends payable - common stock			125.3						—
Customer deposits and credits			261.6						294.4
Taxes accrued			134.7						166.2
Interest accrued			147.4						136.1
Exchange gas payable			56.1						50.5
Regulatory liabilities			151.7						278.6
Asset retirement obligations			74.9						72.5
Accrued compensation and employee benefits			239.3						227.6
Other accruals			151.7						217.4
Total Current Liabilities(1)			3,485.5						5,265.1
Other Liabilities
Deferred income taxes			2,206.7						2,080.4
Accrued liability for postretirement and postemployment benefits			238.4						250.1
Regulatory liabilities			1,437.6						1,510.7
Asset retirement obligations			733.0						480.5
Other noncurrent liabilities and deferred credits			311.8						298.6
Total Other Liabilities(1)			4,927.5						4,620.3
Commitments and Contingencies (Refer to Note 15, "Other Commitments and Contingencies")
Total Capitalization and Liabilities			$	30,828.1					$	31,077.2

(1)Includes $50.5 million and $68.3 million at September 30, 2024 and December 31, 2023, respectively, of current liabilities and $57.7 million and $55.7 million at September 30, 2024 and December 31, 2023, respectively, of other liabilities of consolidated VIEs that creditors do not have recourse to our general credit. Refer to Note 4, "Noncontrolling Interests," for additional information.

The accompanying Notes to Condensed Consolidated Financial Statements (unaudited) are an integral part of these statements.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Condensed Statements of Consolidated Cash Flows (unaudited)

Nine Months Ended September 30, (in millions)			2024						2023
Operating Activities
Net Income			$	600.4					$	482.5
Adjustments to Reconcile Net Income to Net Cash from Operating Activities:
Depreciation and amortization			765.1						650.9
Deferred income taxes and investment tax credits			109.1						102.1
Loss (gain) on sale of assets			1.1						(0.5)
Payments for asset retirement obligations			(55.0)						(25.0)
Other adjustments			(14.9)						12.0
Changes in Assets and Liabilities:
Components of working capital			(85.8)						323.6
Regulatory assets/liabilities			(35.6)						15.1
Deferred charges and other noncurrent assets			(45.1)						(11.8)
Other noncurrent liabilities and deferred credits			2.4						(13.0)
Net Cash Flows from Operating Activities			1,241.7						1,535.9
Investing Activities
Capital expenditures			(1,854.0)						(1,885.6)
Cost of removal			(108.9)						(118.7)
Milestone payments to renewable generation asset developer			(478.8)						(486.7)
Other investing activities			27.2						(12.3)
Net Cash Flows used for Investing Activities			(2,414.5)						(2,503.3)
Financing Activities
Proceeds from issuance of long-term debt			2,229.6						1,488.7
Repayments of finance lease obligations			(20.4)						(24.1)
Repayment of short term credit agreements			(1,650.0)						—
Net change in commercial paper and other short-term borrowings			(1,141.6)						457.8
Issuance of common stock, net of issuance costs			507.9						9.6
Redemption of preferred stock			(486.1)						(393.9)
Preferred stock redemption premium			(14.0)						(6.2)
Equity costs, premiums and other debt related costs			(62.9)						(19.3)
Contributions from NIPSCO minority interest holders			99.5						—
Distribution to NIPSCO minority interest holders			(32.0)						—
Contributions from tax equity partners			—						240.9
Distributions to tax equity partners			(14.3)						(12.0)
Dividends paid - common stock			(357.0)						(310.1)
Dividends paid - preferred stock			(8.2)						(35.7)
Contract liability payment			—						(49.9)
Payment of obligation to renewable generation asset developer			—						(347.2)
Net Cash Flows (used for) from Financing Activities			(949.5)						998.6
Change in cash, cash equivalents and restricted cash			(2,122.3)						31.2
Cash, cash equivalents and restricted cash at beginning of period			2,281.1						75.4
Cash, Cash Equivalents and Restricted Cash at End of Period			$	158.8					$	106.6

Reconciliation to Balance Sheet

Nine Months Ended September 30, (in millions)			2024
Cash and cash equivalents			126.2
Restricted Cash			32.6
Total Cash, Cash Equivalents and Restricted Cash			158.8

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

Supplemental Disclosures of Cash Flow Information

Nine Months Ended September 30, (in millions)			2024						2023
Non-cash transactions:
Capital expenditures included in current liabilities			$	348.0					$	389.0
Dividends declared but not paid			125.3						111.9
Purchase contract liability			—						16.4

The accompanying Notes to Condensed Consolidated Financial Statements (unaudited) are an integral part of these statements.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Condensed Statements of Consolidated Equity (unaudited)

(in millions)			Common Stock						Preferred Stock						Treasury Stock						Additional Paid-In Capital						Retained Deficit						Accumulated Other Comprehensive Loss						Noncontrolling Interest in Consolidated Subsidiaries						Total
Balance as of July 1, 2024			$	4.5					$	—					$	(99.9)					$	8,894.2					$	(896.2)					$	(33.6)					$	1,950.6					$	9,819.6
Comprehensive Income:
Net income			—						—						—						—						85.7						—						11.3						97.0
Other comprehensive income, net of tax			—						—						—						—						—						4.0						—						4.0
Dividends:
Common stock ($0.265 per share)			—						—						—						—						(124.4)						—						—						(124.4)
Noncontrolling Interests:
Contributions from noncontrolling interests			—						—						—						—						—						—						39.8						39.8
Distributions to noncontrolling interests			—						—						—						—						—						—						(17.9)						(17.9)
Stock issuances:
Employee stock purchase plan			—						—						—						1.7						—						—						—						1.7
Long-term incentive plan			—						—						—						8.0						—						—						—						8.0
401(k) and profit sharing			—						—						—						2.2						—						—						—						2.2
ATM program			0.2						—						—						498.6						—						—						—						498.8
Balance as of September 30, 2024			$	4.7					$	—					$	(99.9)					$	9,404.7					$	(934.9)					$	(29.6)					$	1,983.8					$	10,328.8
(in millions)			Common Stock						Preferred Stock						Treasury Stock						Additional Paid-In Capital						Retained Deficit						Accumulated Other Comprehensive Loss						Noncontrolling Interest in Consolidated Subsidiaries						Total
Balance as of January 1, 2024			$	4.5					$	486.1					$	(99.9)					$	8,879.5					$	(967.0)					$	(33.6)					$	1,866.7					$	10,136.3
Comprehensive Income:
Net income			—						—						—						—						536.5						—						63.9						600.4
Other comprehensive income, net of tax			—						—						—						—						—						4.0						—						4.0
Dividends:
Common stock ($1.06 per share)			—						—						—						—						(482.3)						—						—						(482.3)
Preferred stock (See Note 6)			—						—						—						—						(8.1)						—						—						(8.1)
Noncontrolling Interests:
Contributions from noncontrolling interests			—						—						—						—						—						—						99.5						99.5
Distributions to noncontrolling interests			—						—						—						—						—						—						(46.3)						(46.3)
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			—						—						—						4.7						—						—						—						4.7
Long-term incentive plan			—						—						—						14.9						—						—						—						14.9
401(k) and profit sharing			—						—						—						7.0						—						—						—						7.0
ATM program			0.2						—						—						498.6						—						—						—						498.8
Balance as of September 30, 2024			$	4.7					$	—					$	(99.9)					$	9,404.7					$	(934.9)					$	(29.6)					$	1,983.8					$	10,328.8

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

(in millions)			Common Stock						Preferred Stock						Treasury Stock						Additional Paid-In Capital						Retained Deficit						Accumulated Other Comprehensive Loss						Noncontrolling Interest in Consolidated Subsidiaries						Total
Balance as of July 1, 2023			$	4.2					$	1,152.6					$	(99.9)					$	7,383.1					$	(1,173.8)					$	(35.8)					$	341.0					$	7,571.4
Comprehensive Income:
Net income			—						—						—						—						85.1						—						13.3						98.4
Other comprehensive loss, net of tax			—						—						—						—						—						(1.1)						—						(1.1)
Dividends:
Common stock ($0.25 per share)			—						—						—						—						(103.8)						—						—						(103.8)
Preferred stock (See Note 6)			—						—						—						—						(8.1)						—						—						(8.1)
Noncontrolling Interests:
Contributions from noncontrolling interests(1)			—						—						—						—						—						—						204.6						204.6
Distributions to noncontrolling interest			—						—						—						—						—						—						(2.0)						(2.0)
Stock issuances:
Employee stock purchase plan			—						—						—						1.5						—						—						—						1.5
Long-term incentive plan			—						—						—						6.0						—						—						—						6.0
401(k) and profit sharing			—						—						—						2.4						—						—						—						2.4
Balance as of September 30, 2023			$	4.2					$	1,152.6					$	(99.9)					$	7,393.0					$	(1,200.6)					$	(36.9)					$	556.9					$	7,769.3
(1) Contributions from noncontrolling interest is net of transaction costs.
(in millions)			Common Stock						Preferred Stock						Treasury Stock						Additional Paid-In Capital						Retained Deficit						Accumulated Other Comprehensive Loss						Noncontrolling Interest in Consolidated Subsidiaries						Total
Balance as of January 1, 2023			$	4.2					$	1,546.5					$	(99.9)					$	7,375.3					$	(1,213.6)					$	(37.1)					$	326.4					$	7,901.8
Comprehensive Income:
Net income			—						—						—						—						476.9						—						5.6						482.5
Other comprehensive income, net of tax			—						—						—						—						—						0.2						—						0.2
Dividends:
Common stock ($1.00 per share)			—						—						—						—						(413.9)						—						—						(413.9)
Preferred stock (See Note 6)			—						—						—						—						(43.8)						—						—						(43.8)
Noncontrolling Interests:
Contributions from noncontrolling interests(1)			—						—						—						—						—						—						236.9						236.9
Distributions to noncontrolling interest			—						—						—						—						—						—						(12.0)						(12.0)
Stock issuances (redemptions):
Series A Preferred stock redemption			—						(393.9)						—						—						—						—						—						(393.9)
Series A Preferred stock redemption premium			—						—						—						—						(6.2)						—						—						(6.2)
Employee stock purchase plan			—						—						—						4.3						—						—						—						4.3
Long-term incentive plan			—						—						—						5.9						—						—						—						5.9
401(k) and profit sharing			—						—						—						7.5						—						—						—						7.5
Balance as of September 30, 2023			$	4.2					$	1,152.6					$	(99.9)					$	7,393.0					$	(1,200.6)					$	(36.9)					$	556.9					$	7,769.3
(1) Contributions from noncontrolling interest is net of transaction costs.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Condensed Statements of Consolidated Equity (unaudited) (continued)

			Preferred						Common
Shares (in thousands)			Shares						Shares						Treasury						Outstanding
Balance as of July 1, 2024			—						452,362						(3,963)						448,399
Issued:
Employee stock purchase plan			—						59						—						59
Long-term incentive plan			—						32						—						32
401(k) and profit sharing			—						69						—						69
ATM program			—						18,148						—						18,148
Balance as of September 30, 2024			—						470,670						(3,963)						466,707
			Preferred						Common
Shares (in thousands)			Shares						Shares						Treasury						Outstanding
Balance as of January 1, 2024			40						451,345						(3,963)						447,382
Issued:
Employee stock purchase plan			—						170						—						170
Long-term incentive plan			—						761						—						761
401(k) and profit sharing			—						246						—						246
ATM program			—						18,148						—						18,148
Redeemed:
Series B and B-1 Preferred Stock			(40)						—						—						—
Balance as of September 30, 2024			—						470,670						(3,963)						466,707
			Preferred						Common
Shares (in thousands)			Shares						Shares						Treasury						Outstanding
Balance as of July 1, 2023			903						417,112						(3,963)						413,149
Issued:
Employee stock purchase plan			—						54						—						54
Long-term incentive plan			—						33						—						33
401(k) and profit sharing			—						89						—						89
Balance as of September 30, 2023			903						417,288						(3,963)						413,325
			Preferred						Common
Shares (in thousands)			Shares						Shares						Treasury						Outstanding
Balance as of January 1, 2023			1,303						416,106						(3,963)						412,143
Issued:
Equity Units
Employee stock purchase plan			—						155						—						155
Long-term incentive plan			—						754						—						754
401(k) and profit sharing			—						273						—						273
Redeemed:
Series A Preferred Stock			(400)						—						—						—
Balance as of September 30, 2023			903						417,288						(3,963)						413,325

The accompanying Notes to Condensed Consolidated Financial Statements (unaudited) are an integral part of these statements.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

1. Basis of Accounting Presentation

Our accompanying Condensed Consolidated Financial Statements (unaudited) reflect all normal recurring adjustments that are necessary, in the opinion of management, to present fairly the results of operations in accordance with GAAP in the United States of America. The accompanying 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.

The accompanying financial statements should be read in conjunction with the consolidated financial statements and notes thereto included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2023. Income for interim periods may not be indicative of results for the calendar year due to weather variations and other factors.

The Condensed Consolidated Financial Statements (unaudited) have been prepared pursuant to the rules and regulations of the SEC. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations, although we believe that the disclosures made in this Quarterly Report on Form 10-Q are adequate to make the information herein not misleading.

2. Recent Accounting Pronouncements

Recently Issued Accounting Pronouncements

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures. This pronouncement enhances annual and interim disclosure requirements over reportable segments, primarily through enhanced disclosures about significant segment expenses that are regularly provided to or easily computed from information regularly provided to the chief operating decision maker ("CODM") and included within each reported measure of segment profit or loss. The pronouncement also allows for more than one measure of segment profit if the CODM uses more than one measure in assessing segment performance. The pronouncement is effective for annual periods beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024, with early adoption permitted. We will implement and provide the required disclosures beginning in the 2024 Annual Report on Form 10-K.

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 will require 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. This ASU is effective for annual periods beginning after December 15, 2024, with early adoption permitted, and is to be applied on a prospective basis with retrospective application permitted. We will implement and provide the required disclosures beginning in 2025.

3. Revenue Recognition

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 17, "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 the northern part of Indiana for residential, commercial and industrial customers.

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

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

Three months ended September 30, 2024 (in millions)			Columbia Operations						NIPSCO Operations						Corporate and Other						Total
Gas Distribution
Residential			$	296.9					$	66.8					$	—					$	363.7
Commercial			78.3						28.6						—						106.9
Industrial			32.0						16.4						—						48.4
Off-system			7.1						—						—						7.1
Wholesale			0.1						—						—						0.1
Miscellaneous(1)			2.9						1.9						—						4.8
Subtotal			$	417.3					$	113.7					$	—					$	531.0
Electric Generation and Power Delivery
Residential			$	—					$	197.9					$	—					$	197.9
Commercial			—						172.7						—						172.7
Industrial			—						124.8						—						124.8
Wholesale			—						15.0						—						15.0
Public Authority			—						2.0						—						2.0
Miscellaneous(1)			—						2.7						—						2.7
Subtotal			$	—					$	515.1					$	—					$	515.1
Total Customer Revenues**(2)**			417.3						628.8						—						1,046.1
Other Revenues**(3)**			6.1						23.8						0.3						30.2
Total Operating Revenues			$	423.4					$	652.6					$	0.3					$	1,076.3
(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 revenue refunds, public repairs and property rentals. (2)Customer revenue amounts exclude intersegment revenues. See Note 17, "Business Segment Information," for discussion of intersegment revenues. (3)Amounts included in Columbia Operations primarily relate to weather normalization adjustment mechanisms. Amounts included in NIPSCO Operations primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets.
Three months ended September 30, 2023 (in millions)			Columbia Operations						NIPSCO Operations						Corporate and Other						Total
Gas Distribution
Residential			$	282.6					$	69.1					$	—					$	351.7
Commercial			78.5						30.0						—						108.5
Industrial			30.2						16.1						—						46.3
Off-system			9.8						—						—						9.8
Wholesale			0.1						—						—						0.1
Miscellaneous(1)			6.4						2.1						—						8.5
Subtotal			$	407.6					$	117.3					$	—					$	524.9
Electric Generation and Power Delivery
Residential			$	—					$	176.0					$	—					$	176.0
Commercial			—						156.6						—						156.6
Industrial			—						115.9						—						115.9
Wholesale			—						15.2						—						15.2
Public Authority			—						1.6						—						1.6
Miscellaneous(1)			—						12.4						—						12.4
Subtotal			$	—					$	477.7					$	—					$	477.7
Total Customer Revenues**(2)**			407.6						595.0						—						1,002.6
Other Revenues**(3)**			3.4						21.2						0.2						24.8
Total Operating Revenues			$	411.0					$	616.2					$	0.2					$	1,027.4
(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 revenue refunds, public repairs and property rentals. (2)Customer revenue amounts exclude intersegment revenues. See Note 17, "Business Segment Information," for discussion of intersegment revenues. (3)Amounts included in Columbia Operations are primarily relate to weather normalization adjustment mechanisms. Amounts included in NIPSCO Operations primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

Nine months ended September 30, 2024 (in millions)			Columbia Operations						NIPSCO Operations						Corporate and Other						Total
Gas Distribution
Residential			$	1,257.2					$	357.5					$	—					$	1,614.7
Commercial			395.6						134.0						—						529.6
Industrial			105.1						56.3						—						161.4
Off-system			30.5						—						—						30.5
Wholesale			1.1						—						—						1.1
Miscellaneous(1)			15.4						12.5						—						27.9
Subtotal			$	1,804.9					$	560.3					$	—					$	2,365.2
Electric Generation and Power Delivery
Residential			$	—					$	498.6					$	—					$	498.6
Commercial			—						470.0						—						470.0
Industrial			—						360.4						—						360.4
Wholesale			—						32.4						—						32.4
Public Authority			—						6.0						—						6.0
Miscellaneous(1)			—						10.6						—						10.6
Subtotal			$	—					$	1,378.0					$	—					$	1,378.0
Total Customer Revenues**(2)**			1,804.9						1,938.3						—						3,743.2
Other Revenues**(3)**			59.6						63.9						0.6						124.1
Total Operating Revenues			$	1,864.5					$	2,002.2					$	0.6					$	3,867.3
(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 revenue refunds, public repairs and property rentals. (2)Customer revenue amounts exclude intersegment revenues. See Note 17, "Business Segment Information," for discussion of intersegment revenues. (3)Amounts included in Columbia Operations primarily relate to weather normalization adjustment mechanisms. Amounts included in NIPSCO Operations primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets.
Nine months ended September 30, 2023 (in millions)			Columbia Operations						NIPSCO Operations						Corporate and Other						Total
Gas Distribution
Residential			$	1,311.9					$	477.4					$	—					$	1,789.3
Commercial			435.5						185.7						—						621.2
Industrial			102.9						66.4						—						169.3
Off-system			49.9						—						—						49.9
Wholesale			1.5						—						—						1.5
Miscellaneous(1)			26.3						10.9						—						37.2
Subtotal			$	1,928.0					$	740.4					$	—					$	2,668.4
Electric Generation and Power Delivery
Residential			$	—					$	449.2					$	—					$	449.2
Commercial			—						437.6						—						437.6
Industrial			—						362.7						—						362.7
Wholesale			—						25.5						—						25.5
Public Authority			—						5.5						—						5.5
Miscellaneous(1)			—						17.0						—						17.0
Subtotal			$	—					$	1,297.5					$	—					$	1,297.5
Total Customer Revenues**(2)**			1,928.0						2,037.9						—						3,965.9
Other Revenues**(3)**			53.5						63.4						0.6						117.5
Total Operating Revenues			$	1,981.5					$	2,101.3					$	0.6					$	4,083.4
(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 revenue refunds, public repairs and property rentals. (2)Customer revenue amounts exclude intersegment revenues. See Note 17, "Business Segment Information," for discussion of intersegment revenues. (3)Amounts included in Columbia Operations are primarily relate to weather normalization adjustment mechanisms. Amounts included in NIPSCO Operations primarily relate to MISO multi-value projects and revenue from non-jurisdictional transmission assets.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

Customer Accounts Receivable. Accounts receivable on our Condensed Consolidated Balance Sheets (unaudited) 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 the 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 nine months ended September 30, 2024 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, 2023			$	479.4					$	337.6
Balance as of September 30, 2024			350.4						198.8

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 collectibility. 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 supportable forecasts. Internal and external inputs are used in our credit model including, but not limited to, energy consumption trends, revenue projections, actual charge-offs data, recoveries data, shut-offs, customer delinquencies, final bill data, and inflation. 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.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

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 September 30, 2024 and December 31, 2023 are presented in the table below:

(in millions)			Columbia Operations						NIPSCO Operations												Corporate and Other						Total
Balance as of January 1, 2024			$	10.2					$	11.9											$	0.8					$	22.9
Current period provisions			18.9						9.3												—						28.2
Write-offs charged against allowance			(34.3)						(7.9)												(0.8)						(43.0)
Recoveries of amounts previously written off			8.9						0.7												—						9.6
Balance as of September 30, 2024			$	3.7					$	14.0											$	—					$	17.7

(in millions)			Columbia Operations						NIPSCO Operations												Corporate and Other						Total
Balance as of January 1, 2023			$	11.1					$	12.0											$	0.8					$	23.9
Current period provisions			28.3						11.5												—						39.8
Write-offs charged against allowance			(49.2)						(12.4)												—						(61.6)
Recoveries of amounts previously written off			20.0						0.8												—						20.8
Balance as of December 31, 2023			$	10.2					$	11.9											$	0.8					$	22.9

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. NIPSCO is a member of JVs that own and operate two wind facilities, Rosewater and Indiana Crossroads Wind, which have 102 MW and 302 MW of nameplate capacity, respectively. NIPSCO is also a member of JVs that own two solar facilities, 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 the 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 during the quarter that was not previously contractually required.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

Our Condensed Consolidated Balance Sheets (unaudited) included the following assets and liabilities associated with VIEs.

(in millions)			September 30, 2024						December 31, 2023
Net Property, Plant and Equipment			$	1,335.3					$	1,369.8
Current assets			52.9						63.6
Total assets(1)			1,388.2						1,433.4
Current liabilities			50.5						68.3
Asset retirement obligations			57.7						55.7
Total liabilities(1)(2)			$	108.2					$	124.0

(1)The assets of each consolidated VIE can only be used 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 September 30, 2024.

Voting Interest Entities. On December 31, 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. During the three and nine months ended September 30, 2024, we received $39.8 million and $99.5 million of contributions, respectively, and we made $11.8 million and $32.0 million of distributions, respectively, to our NIPSCO minority interest holders based on their relative ownership percentages.

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 (See Note 6, "Equity,"). For the purposes of determining diluted EPS, for the three and nine months ended September 30, 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. A numerator adjustment was reflected in the calculation of diluted EPS for interest expense incurred in the three and nine months ended September 30, 2023, net of tax, related to the purchase contracts. The purchase contracts were settled on December 1, 2023.

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.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

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

			Three Months Ended September 30,												Nine Months Ended September 30,
(in millions, except per share amounts)			2024						2023						2024						2023
Numerator:
Net Income Available to Common Shareholders			$	85.7					$	77.0					$	515.8					$	436.1
Less: Income allocated to participating securities			0.2						0.1						0.9						0.3
Net Income Available to Common Shareholders - Basic			85.5						76.9						514.9						435.8
Add: Dilutive effect of Equity Units			—						0.4						—						1.2
Net Income Available to Common Shareholders - Diluted			$	85.5					$	77.3					$	514.9					$	437.0
Denominator:
Average common shares outstanding - Basic			451.9						413.5						449.4						413.2
Dilutive potential common shares:
Equity Units purchase contracts			—						33.1						—						31.9
Equity Units purchase contract payment balance			—						0.6						—						1.2
Shares contingently issuable under employee stock plans			0.9						0.7						0.9						0.7
Shares restricted under employee stock plans			0.3						0.4						0.3						0.4
ATM forward sale agreements			1.4						—						0.8						—
Average Common Shares - Diluted			454.5						448.3						451.4						447.4
Earnings per common share:
Basic			$	0.19					$	0.19					1.15						1.05
Diluted			$	0.19					$	0.17					1.14						0.98

6. Equity

ATM Program. In February 2024, we entered into eight separate equity distribution agreements pursuant to which we are able to sell up to an aggregate of $900.0 million of our common stock.

In February 2024, under the ATM program, 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 7,757,951 shares from third parties, which the forward purchaser sold, through its affiliated agent, at a weighted average price of $25.78 per share. On September 17, 2024 we settled all the shares under the forward sale agreement for $199.9 million, based on a net price of $25.77 per share.

In May 2024, under the ATM program, 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 10,390,000 shares from third parties, which the forward purchaser sold, through its affiliated agent, at a weighted average price of $28.87 per share. On September 11, 2024 we settled all the shares under the forward sale agreement for $299.1 million, based on a net price of $28.79 per share.

In September 2024, under the ATM program, 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 1,495,949 shares from third parties, which the forward purchaser sold, through its affiliated agent, at a weighted average price of $34.01 per share. We may settle the forward sale agreement in shares, cash or net shares, by October 30, 2025. Had we settled all the shares under the forward sale agreement at September 30, 2024, we would have received approximately $50.4 million, based on a net price of $33.72 per share.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

In September 2024, under the ATM program, we executed a second forward sale agreement, which allows us to issue a fixed number of shares at a price to be settled in the future. The forward purchasers under our forward sale agreement borrowed 1,500,000 shares from third parties, which the forward purchaser sold, through its affiliated agent, at a weighted average price of $34.32 per share. We may settle the forward sale agreement in shares, cash or net shares between October 1, 2024, and October 30, 2025. Had we settled all the shares under the forward sale agreement at October 1, 2024, we would have received approximately $51.1 million, based on a net price of $34.06 per share.

As of September 30, 2024, the ATM program (inclusive of open forward sale agreements) had approximately $297.7 million of equity available for issuance. The program expires on December 31, 2025.

Series A Preferred Stock. There were no dividends declared per share for the Series A Preferred Stock during the three months ended September 30, 2024 and 2023. Dividends declared per share for the Series A Preferred Stock were zero and $28.25 during the nine months ended September 30, 2024 and 2023, respectively.

On June 15, 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. Dividends declared per share for the Series B Preferred Stock were zero and $406.25 during the three months ended September 30, 2024 and 2023, respectively. Dividends declared per share for the Series B Preferred Stock were $406.25 and $1,625.0 during the nine months ended September 30, 2024 and 2023, respectively.

On March 15, 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 have not recognized 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 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.

Equity Units. On December 1, 2023, we issued 33,898,837 shares of our common stock under the purchase contract component of the Corporate Units. As of December 1, 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.

Refer to Note 5, "Earnings Per Share," for additional information regarding our treatment of the Equity Units for diluted EPS during 2023.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

7. Short-Term Borrowings

We generate short-term borrowings from our revolving credit facility, commercial paper program, accounts receivable transfer programs, and term credit agreements. 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, provide for issuance of letters of credit and also for general corporate purposes. Our revolving credit facility has a program limit of $1.85 billion and is comprised of a syndicate of banks. We had no outstanding borrowings under this facility as of September 30, 2024 and December 31, 2023.

Commercial Paper Program. On February 9, 2024 we increased our commercial paper program limit from $1.50 billion to $1.85 billion. We had $257.0 million and $1,061.0 million of commercial paper outstanding with weighted-average interest rates of 4.95% and 5.65% as of September 30, 2024 and December 31, 2023, 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 2025 and October 2025 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.

Transfers of accounts receivable are accounted for as secured borrowings resulting in the recognition of short-term borrowings on the Condensed Consolidated Balance Sheets (unaudited). As of September 30, 2024, the maximum amount of debt that could be borrowed related to our accounts receivable programs was $225.0 million.

We had zero and $337.6 million of short-term borrowings related to the securitization transactions as of September 30, 2024 and December 31, 2023, respectively.

For the nine months ended September 30, 2024 and 2023, $337.6 million and $62.2 million, respectively were 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 $0.4 million and $0.5 million for the three months ended September 30, 2024 and 2023, and $1.3 million and $2.1 million for the nine months ended September 30, 2024 and 2023, respectively. Columbia of Ohio, NIPSCO and Columbia of Pennsylvania remain responsible for collecting on the receivables securitized, and the receivables cannot be transferred to another party.

Term Credit Agreements. At December 31, 2023, we had $1.0 billion, and $650.0 million outstanding under term credit agreements with interest rates of 6.41% and 6.50%, respectively. On January 3, 2024, we terminated and repaid in full our $1.0 billion term credit agreement and our $650.0 million term credit agreement with proceeds from the NIPSCO Minority Interest Transaction.

Items listed above, excluding the term credit agreements, are presented net in the Condensed Statements of Consolidated Cash Flows (unaudited) as their maturities are less than 90 days.

8. Long-Term Debt

On March 14, 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.

On May 16, 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 16, 2024 to, but excluding, November 30, 2029 at a rate of 6.950% per annum and (ii) from and including November 30, 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 dated May 13, 2024, which was filed with the SEC on May 14, 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

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

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. The subordinated notes were issued pursuant to a Subordinated Indenture, dated as of May 16, 2024, between us and The Bank of New York Mellon, as trustee, as supplemented by the First Supplemental Indenture thereto, dated as of May 16, 2024.

On June 24, 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.

On September 9, 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 9, 2024 to, but excluding, March 31, 2035 at a rate of 6.375% per annum and (ii) from and including March 31, 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 dated September 3, 2024, which was filed with the SEC on September 4, 2024) as of the then most recent reset interest determination date plus a spread of 2.527%, 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. The subordinated notes were issued pursuant to a Subordinated Indenture, dated as of May 16, 2024, between us and The Bank of New York Mellon, as trustee, as supplemented by the Second Supplemental Indenture thereto, dated as of September 9, 2024.

9. Asset Retirement Obligations

During the third quarter of 2024, 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, we recorded an increase of $164.6 million based on initial assessments of estimated costs to comply with the EPA rule for certain sites. Additional costs would be recorded when they become probable and estimable. These costs are expected to be recoverable through existing and future depreciation rates. See Note 15, "Other Commitments and Contingencies - C. Environmental Matters," for additional information on the legacy CCR rule.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

10. Regulatory Matters

Renewable generation filings

In March 2024, NIPSCO filed a petition with the IURC to issue an order modifying its November 22, 2023 order to approve direct ownership of the Gibson project. Also, in March 2024, NIPSCO filed a petition with the IURC to issue an order modifying its June 29, 2021 order to approve direct ownership of the Fairbanks project. Hearings for both the Gibson project and Fairbanks project were held in June 2024 and July 2024, respectively, with orders approving direct ownership of both projects received in August 2024.

WAM system filing

In March 2024, NIPSCO filed a petition with the IURC for authority to defer, as a regulatory asset, 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. These improvements are part of our enterprise-wide transformation roadmap which seeks to optimize our field work and reduce enterprise risk. The petition also included the confirmation that the WAM program assets, including the requested regulatory assets, will be included in NIPSCO's rate base for ratemaking purposes in rate cases after the WAM assets have been placed in service. The hearing was held in August 2024, and a final order approving NIPSCO's request was issued in September 2024 and NIPSCO recorded a deferral resulting in a regulatory asset of $16.9 million.

NIPSCO Gas Peaker filing

In September 2023, NIPSCO filed a request for issuance of a certificate of public convenience and necessity for an approximately 400 MW natural gas peaking generation facility with the IURC, which was supplemented in January 2024 based on updates on availability of certain key equipment. A final order was received in October 2024 approving the request.

Columbia of Virginia CARE Plan

On May 22, 2024, Columbia Gas of Virginia filed an application for approval to amend and extend its Conservation and Ratemaking Efficiency ("CARE") Plan. In September 2024, the Virginia State Corporation Commission issued its final order determining that the CARE Plan meets the requirements and approved the plan with all proposed measures effective January 1, 2025 through December 31, 2027.

Regulatory deferral related to renewable energy investments

In accordance with the accounting principles of ASC 980, 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 and amortization" on the Condensed Statements of Consolidated Income (unaudited). NiSource recorded depreciation expense of $24.2 million and $40.8 million for the three and nine months ended September 30, 2024, and a decrease to depreciation expense of $19.0 million and $9.7 million for the three and nine months ended September 30, 2023, respectively. Following the implementation of the NIPSCO electric base rate case implemented in August 2023, we began recognizing amounts to recover our investments of projects that have been placed in service. Refer to Note 4, "Noncontrolling Interests," for additional information.

11. Risk Management Activities

We are exposed to certain risks relating 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 lower our cost of debt capital, manage our interest rate exposure and limit volatility in the price of natural gas.

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 on behalf of our customers, associated with natural gas purchases or sales by economically hedging the various gas cost components using a combination of

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

futures, options, forwards or other derivative contracts. At September 30, 2024 and December 31, 2023, we had 64.4 MMDth and 76.1 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 September 30, 2024, 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. The hedging program was executed in December 2023, with an effective date of April 1, 2024 and will continue in perpetuity. The program is designed to financially hedge approximately 20% of the customer’s annual demand. All unrealized gains and losses on these derivative contracts are deferred as regulatory liabilities or assets and all realized gains and losses are remitted to or collected from customers through the relevant cost recovery mechanism.

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

			September 30, 2024												December 31, 2023
(in millions)			Assets						Liabilities						Assets						Liabilities
Current(1)
Derivatives not designated as hedging instruments			$	4.1					$	3.7					$	1.1					$	7.5
Total			$	4.1					$	3.7					$	1.1					$	7.5
Noncurrent(2)
Derivatives not designated as hedging instruments			$	14.8					$	3.0					$	22.2					$	1.9
Total			$	14.8					$	3.0					$	22.2					$	1.9

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

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

Our commodity price risk management 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 September 30, 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 $12.2 million and $13.9 million at September 30, 2024 and December 31, 2023, respectively.

The following table summarizes the gains and losses associated with the commodity price risk programs deferred as regulatory assets and liabilities:

(in millions)			September 30, 2024						December 31, 2023
Regulatory Assets
Losses on commodity price risk programs			$	11.8					$	24.4
Regulatory Liabilities
Gains on commodity price risk programs			19.2						23.3

Our derivative instruments measured at fair value as of September 30, 2024 and December 31, 2023 do not contain any credit-risk-related contingent features.

Derivatives Designated as Hedging Instruments Interest rate risk management. As of September 30, 2024 and December 31, 2023 we had no active interest rate swap positions. The overall net loss related to settled interest rate swaps is recorded in AOCI. We amortize the net loss over the life of the debt associated with these swaps as we recognize interest expense. These amounts are immaterial for the three and nine months ended September 30, 2024 and 2023 and are recorded in "Interest expense, net" on the Condensed Statements of Consolidated Income (unaudited). Amounts expected to be reclassified to earnings during the next twelve months are immaterial. See Note 16, "Accumulated Other Comprehensive Loss," for additional information.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

12. 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 Condensed Consolidated Balance Sheets (unaudited) on a recurring basis and their level within the fair value hierarchy as of September 30, 2024 and December 31, 2023:

Recurring Fair Value Measurements September 30, 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 September 30, 2024
Assets
Risk management assets			$	—					$	18.9					$	—					$	18.9
Available-for-sale debt securities			—						137.9						—						137.9
Total			$	—					$	156.8					$	—					$	156.8
Liabilities
Risk management liabilities			$	—					$	6.7					$	—					$	6.7
Total			$	—					$	6.7					$	—					$	6.7

Recurring Fair Value Measurements December 31, 2023 (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, 2023
Assets
Risk management assets			$	—					$	23.3					$	—					$	23.3
Available-for-sale debt securities			—						159.1						—						159.1
Total			$	—					$	182.4					$	—					$	182.4
Liabilities
Risk management liabilities			$	—					$	9.4					$	—					$	9.4
Total			$	—					$	9.4					$	—					$	9.4

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.

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.

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.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

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.

Credit risk is considered in the fair value calculation of derivative instruments that are not exchange-traded. Credit exposures are adjusted to reflect collateral agreements that reduce exposures. As of September 30, 2024 and December 31, 2023, 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.

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 11, "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. As of September 30, 2024 and December 31, 2023, we have $0.2 million and $0.6 million, respectively, recorded as an allowance for credit losses on available-for-sale debt securities as a result of the analysis described above. Continuous credit monitoring and portfolio credit balancing mitigates our risk of credit losses on our available-for-sale debt securities.

The amortized cost, gross unrealized gains and losses, allowance for credit losses, and fair value of available-for-sale securities at September 30, 2024 and December 31, 2023 were:

September 30, 2024 (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			$	49.1					$	—					$	(1.9)					$	—					$	47.2
Corporate/Other debt securities			94.4						1.1						(4.6)						(0.2)						90.7
Total			$	143.5					$	1.1					$	(6.5)					$	(0.2)					$	137.9
December 31, 2023 (in millions)			Amortized Cost						Gross Unrealized Gains						Gross Unrealized Losses**(2)**						Allowance for Credit Losses						Fair Value
Available-for-sale debt securities
U.S. Treasury debt securities			$	63.8					$	—					$	(3.2)					$	—					$	60.6
Corporate/Other debt securities			105.2						0.8						(6.9)						(0.6)						98.5
Total			$	169.0					$	0.8					$	(10.1)					$	(0.6)					$	159.1

(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 $41.2 million and $66.5 million, respectively, at September 30, 2024.

(2)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 $58.7 million and $74.8 million, respectively, at December 31, 2023.

Net realized gains and losses on available-for-sale securities were $0.1 million and $0.5 million for the three and nine months ended September 30, 2024, and zero and $0.6 million for the three and nine months ended September 30, 2023.

The cost of maturities sold is based upon specific identification. At September 30, 2024 there were no U.S. Treasury debt securities or Corporate/Other debt securities with maturities of less than a year. At December 31, 2023, approximately $16.8 million of U.S. Treasury debt securities and approximately $4.9 million of Corporate/Other debt securities had maturities of less than a year.

Non-recurring Fair Value Measurements

We measure the fair value of certain assets, primarily 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.

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. As of September 30, 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:

(in millions)			Carrying Amount as of September 30, 2024						Estimated Fair Value as of September 30, 2024						Carrying Amount as of Dec. 31, 2023						Estimated Fair Value as of Dec. 31, 2023
Long-term debt (including current portion)			$	13,357.5					$	12,926.5					$	11,079.3					$	10,370.9

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

13. Income Taxes

Our interim effective tax rates reflect the estimated annual effective tax rates for 2024 and 2023 applied to year-to-date pretax income, adjusted for tax expense associated with certain discrete items. The effective tax rates for the three months ended September 30, 2024 and 2023 were 14.1% and 3.7%, respectively. The effective tax rates for the nine months ended September 30, 2024 and 2023 were 15.4% and 17.7%, respectively. These effective tax rates differ from the federal statutory tax rate of 21% primarily due to renewable partnership income, amortization of excess deferred federal income tax liabilities, as specified in the TCJA, tax credits, state flow through, and other permanent book-to-tax differences.

The increase in the three-month effective tax rate of 10.4% in 2024 compared to 2023 was driven by higher renewable partnership income in 2023 resulting from HLBV allocation of earnings due to solar projects going into service, offset by higher non-taxable AFUDC equity recorded on higher construction work in process balances in the current quarter.

As of September 30, 2024, there have been no material changes to our unrecognized tax benefits or possible changes that could reasonably be expected to occur during the next twelve months. See Note 15 to the Company’s Consolidated Financial Statements in the Annual Report on Form 10-K for the year ended December 31, 2023, for a discussion of these unrecognized tax benefits.

14. 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. The majority of such 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. We determined that, for certain rate-regulated subsidiaries, the future recovery of postretirement benefit costs is probable, and we record regulatory assets and liabilities for amounts that would otherwise have been recorded to expense or accumulated other comprehensive loss. Current rates of rate-regulated companies include postretirement benefit costs, including amortization of the regulatory assets and liabilities that arose prior to inclusion of these costs in rates. For most plans, cash contributions are remitted to grantor trusts.

For the nine months ended September 30, 2024 and 2023, we contributed $1.9 million and $2.6 million, respectively to our pension plans and $18.3 million and $16.7 million, respectively to our OPEB plans.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

The following table provides the components of the plans' actuarially determined net periodic benefit cost for the three and nine months ended September 30, 2024 and 2023:

			Pension Benefits												OPEB
Three Months Ended September 30, (in millions)			2024						2023						2024						2023
Components of Net Periodic Benefit Cost**(1)**
Service cost			$	5.5					$	5.1					$	1.3					$	1.3
Interest cost			16.3						17.1						5.5						5.4
Expected return on assets			(23.8)						(23.6)						(4.0)						(3.8)
Amortization of prior service credit			—						—						(0.4)						(0.5)
Recognized actuarial loss			7.2						8.4						0.8						0.8
Settlement loss			5.9						7.4						—						—
Total Net Periodic Benefit Cost			$	11.1					$	14.4					$	3.2					$	3.2
(1)The service cost component and all non-service cost components of net periodic benefit (income) cost are presented in "Operation and maintenance" and "Other, net," respectively, on the Condensed Statements of Consolidated Income (unaudited).
			Pension Benefits												OPEB
Nine Months Ended September 30, (in millions)			2024						2023						2024						2023
Components of Net Periodic Benefit Cost**(1)**
Service cost			$	16.4					$	15.3					$	3.9					$	3.9
Interest cost			48.9						51.3						16.4						16.3
Expected return on assets			(71.4)						(70.8)						(12.0)						(11.4)
Amortization of prior service credit			—						—						(1.2)						(1.5)
Recognized actuarial loss			21.6						25.2						2.4						2.4
Settlement loss			5.9						7.5						—						—
Total Net Periodic Benefit Cost			$	21.4					$	28.5					$	9.5					$	9.7
(1)The service cost component and all non-service cost components of net periodic benefit (income) cost are presented in "Operation and maintenance" and "Other, net," respectively, on the Condensed Statements of Consolidated Income (unaudited).

During the third quarter of 2024, the requirements for settlement accounting were met for one of our pension plans, resulting in a settlement charge of $5.9 million for the three months ended September 30, 2024.

15. Other Commitments and Contingencies

A. 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 a 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 the subsidiaries' intended commercial purposes. As of September 30, 2024 and December 31, 2023, we had issued stand-by letters of credit of $9.4 million and $9.9 million, respectively for the benefit of third parties.

We provide guarantees related to our future performance under BTAs for our renewable generation projects. At September 30, 2024 and December 31, 2023, our guarantees for multiple BTAs totaled $1,150.2 million and $646.1 million, respectively. The amount of each guaranty will decrease upon the substantial completion of the construction of the facilities. See ''- D. Other Matters - Generation Transition,'' below for more information.

B. 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 matters were decided against us, the effects could be material to

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

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 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.

C. 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 a majority of environmental assessment and remediation costs and asset retirement costs, further described below, to be recoverable through rates.

As of September 30, 2024 and December 31, 2023, we had recorded a liability of $92.6 million and $80.0 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 Condensed Consolidated Balance Sheets (unaudited). 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 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 Condensed Consolidated Financial Statements (unaudited).

MGP. We maintain a program to identify and investigate former MGP sites where our subsidiaries or predecessors may have liability. The program has identified 51 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.

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. We recorded an $11.2 million increase to the estimated future remediation costs as a result of the refresh completed in the second quarter of 2024. No material changes to the estimated future remediation costs were noted as a result of an internal quarterly review of environmental reserves completed as of September 30, 2024. Our total estimated liability related to the facilities subject to remediation was $87.9 million and $73.7 million at September 30, 2024 and December 31, 2023, 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 $16.4 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.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

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. In the second quarter of 2024, we accrued an immaterial amount to cover probable and estimable costs related to these activities. In the third quarter of 2024, we accrued an additional $164.6 million to cover probable and estimable compliance activities associated with the Legacy CCR Rule. Applicability determinations for legacy impoundments are due when the rule becomes effective on November 8, 2024. Facility evaluations for CCRMUs are required by February 2026 and 2027. 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.

D. Other Matters.

Generation Transition. NIPSCO has executed several BTAs with developers to construct renewable generation facilities. NIPSCO has received IURC approval for all of its BTAs and PPAs. In addition to IURC approval, NIPSCO's purchase obligation under the BTAs is dependent on timely completion of construction. Certain agreements require NIPSCO to make partial payments upon the developer's completion of significant construction milestones. With respect to BTAs for which tax equity partnerships are utilized once the tax equity partner has earned its negotiated rate of return and we have reached the agreed upon contractual date, NIPSCO has the option to purchase at fair market value the remaining interest in the JV from the tax equity partner. In January 2024, the IURC approved the full ownership of Cavalry and Dunns Bridge II, which will allow those BTAs to be executed through direct ownership. In March 2024, Cavalry achieved mechanical completion, resulting in NIPSCO making a $110.6 million payment to the developer. In May 2024, Cavalry achieved substantial completion and commencement of commercial operations, resulting in NIPSCO making a $114.9 million payment to the developer. In August 2024, the IURC approved full ownership of the Gibson and Fairbanks projects and modification of the cost of the Fairbanks project as contemplated in the contractual actions referenced above. In September 2024, Dunns Bridge II achieved mechanical completion, resulting in NIPSCO making a $153.3 million payment to the developer. NIPSCO will file a future request to modify the ownership structure for the Templeton wind project to become a wholly owned project.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

16. Accumulated Other Comprehensive Loss

The following tables display the components 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 July 1, 2024			$	(7.6)					$	(13.0)					$	(13.0)					$	(33.6)
Other comprehensive income (loss) before reclassifications			3.5						0.4						(0.1)						3.8
Amounts reclassified from accumulated other comprehensive loss			—						(0.5)						0.7						0.2
Net current-period other comprehensive income (loss)			3.5						(0.1)						0.6						4.0
Balance as of September 30, 2024			$	(4.1)					$	(13.1)					$	(12.4)					$	(29.6)
(1)All amounts are net of tax. Amounts in parentheses indicate debits.
(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 January 1, 2024			$	(7.3)					$	(12.8)					$	(13.5)					$	(33.6)
Other comprehensive income (loss) before reclassifications			2.8						—						(0.1)						2.7
Amounts reclassified from accumulated other comprehensive loss			0.4						(0.3)						1.2						1.3
Net current-period other comprehensive income (loss)			3.2						(0.3)						1.1						4.0
Balance as of September 30, 2024			$	(4.1)					$	(13.1)					$	(12.4)					$	(29.6)

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

(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 July 1, 2023			$	(10.4)					$	(12.7)					$	(12.7)					$	(35.8)
Other comprehensive income (loss) before reclassifications			(1.7)						(0.4)						(0.1)						(2.2)
Amounts reclassified from accumulated other comprehensive loss			—						0.3						0.8						1.1
Net current-period other comprehensive income (loss)			(1.7)						(0.1)						0.7						(1.1)
Balance as of September 30, 2023			$	(12.1)					$	(12.8)					$	(12.0)					$	(36.9)
(1)All amounts are net of tax. Amounts in parentheses indicate debits.
(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 January 1, 2023			$	(11.2)					$	(12.6)					$	(13.3)					$	(37.1)
Other comprehensive income (loss) before reclassifications			(1.4)						(0.4)						0.2						(1.6)
Amounts reclassified from accumulated other comprehensive loss			0.5						0.2						1.1						1.8
Net current-period other comprehensive income (loss)			(0.9)						(0.2)						1.3						0.2
Balance as of September 30, 2023			$	(12.1)					$	(12.8)					$	(12.0)					$	(36.9)

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

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

17. 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. Our operations are now evaluated through two primary reportable segments, Columbia Operations and NIPSCO Operations. 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 Northwest Indiana.

The remainder of our operations, which are not significant enough on a stand-alone basis to warrant treatment as a reportable segment, are presented as "Corporate and Other" and primarily are comprised of interest expense on holding company debt, and unallocated corporate costs and activities. 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. Our CODM uses operating income as the primary measurement for each of the reported segments and makes decisions on financing, dividends, and taxes at the corporate level on a consolidated basis. 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.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

			Three Months Ended September 30,												Nine Months Ended September 30,
(in millions)			2024						2023						2024						2023
Operating Revenues
Columbia Operations
Unaffiliated			$	423.4					$	411.0					$	1,864.5					$	1,981.5
Intersegment			3.3						3.0						9.6						9.1
Total			426.7						414.0						1,874.1						1,990.6
NIPSCO Operations
Unaffiliated			652.6						616.2						2,002.2						2,101.3
Intersegment			0.3						0.4						0.8						0.8
Total			652.9						616.6						2,003.0						2,102.1
Corporate and Other
Unaffiliated			0.3						0.2						0.6						0.6
Intersegment			145.6						121.7						424.5						361.2
Total			145.9						121.9						425.1						361.8
Eliminations			(149.2)						(125.1)						(434.9)						(371.1)
Consolidated Operating Revenues			$	1,076.3					$	1,027.4					$	3,867.3					$	4,083.4
Operating Income
Columbia Operations			$	41.2					$	54.6					$	499.8					$	507.5
NIPSCO Operations			171.3						173.1						530.0						413.9
Corporate and Other			5.8						5.3						8.9						11.5
Consolidated Operating Income			$	218.3					$	233.0					$	1,038.7					$	932.9

The following table provides information about the assets of our reportable segments included in the Condensed Consolidated Balance Sheet (unaudited):

(in millions)			September 30, 2024						December 31, 2023
Assets
Columbia Operations			$	14,174.1					$	13,664.5
NIPSCO Operations			15,450.1						13,962.6
Corporate and Other			1,203.9						3,450.1
Consolidated Assets			$	30,828.1					$	31,077.2

Information about our reportable segments for the nine months ended September 30, 2023, as well as for the period ended December 31, 2023 has been recast to align with the current year's presentation.

Table of Contents

ITEM 1. FINANCIAL STATEMENTS (continued)

NiSource Inc.

Notes to Condensed Consolidated Financial Statements (unaudited) (continued)

18. Other, Net

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

			Three Months Ended September 30,												Nine Months Ended September 30,
(in millions)			2024						2023						2024						2023
Interest income			$	3.4					$	2.7					$	7.8					$	6.3
AFUDC equity			32.1						6.0						56.7						15.2
Pension and other postretirement non-service cost			(5.9)						(9.8)						(10.2)						(18.2)
Miscellaneous			(0.4)						(0.5)						(2.9)						(1.4)
Total Other, net			$	29.2					$	(1.6)					$	51.4					$	1.9

Table of Contents