Cover and table of contents

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

			☑			ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended December 31, 2024

OR

			☐			TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d)

OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission file number 001-16189

NiSource Inc.

(Exact name of registrant as specified in its charter)

DE									35-2108964
(State or other jurisdiction of incorporation or organization)									(I.R.S. Employer Identification No.)
801 East 86th Avenue
Merrillville,			IN						46410
(Address of principal executive offices)									(Zip Code)

(877) 647-5990

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:

Title of Each Class			Trading Symbol(s)			Name of Each Exchange on Which Registered
Common Stock, par value $0.01 per share			NI			NYSE

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act. Yes þ No ¨

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Act. Yes ¨ No þ

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Yes þ No ¨

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

Yes þ No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definition of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and "emerging growth company" in Rule 12-b-2 of the Exchange Act.

Large accelerated filer þ Accelerated Filer ¨ Emerging Growth Company ☐ Non-accelerated Filer ¨ Smaller Reporting Company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report. ☑

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrants included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive-based compensation received by any of the registrant's executive officers during the relevant recovery period pursuant to §240. 10D-1(b).☐

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Act). Yes ☐ No þ

The aggregate market value of the registrant's common stock, par value $0.01 per share (the "Common Stock") held by non-affiliates was approximately $13,022,151,904 based upon the June 30, 2024, closing price of $28.81 on the New York Stock Exchange.

There were 469,939,639 shares of Common Stock outstanding as of February 5, 2025.

Documents Incorporated by Reference

Part III of this report incorporates by reference specific portions of the Registrant’s Notice of Annual Meeting and Proxy Statement relating to the Annual Meeting of Stockholders to be held on May 12, 2025.

CONTENTS

						Page No.
Defined Terms						3
Part I
Item 1.			Business			7
Item 1A.			Risk Factors			17
Item 1B.			Unresolved Staff Comments			31
Item 1C.			Cybersecurity			31
Item 2.			Properties			32
Item 3.			Legal Proceedings			32
Item 4			Mine Safety Disclosures			32
Part II
Item 5.			Market for Registrant’s Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities			33
Item 6.			Reserved			34
Item 7.			Management’s Discussion and Analysis of Financial Condition and Results of Operations			35
Item 7A.			Quantitative and Qualitative Disclosures About Market Risk			56
Item 8.			Financial Statements and Supplementary Data			57
Item 9.			Changes in and Disagreements With Accountants on Accounting and Financial Disclosure			122
Item 9A.			Controls and Procedures			122
Item 9B.			Other Information			124
Item 9C.			Disclosure Regarding Foreign Jurisdictions that Prevent Inspections			124
Part III
Item 10.			Directors, Executive Officers and Corporate Governance			125
Item 11.			Executive Compensation			125
Item 12.			Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters			125
Item 13.			Certain Relationships and Related Transactions, and Director Independence			125
Item 14.			Principal Accounting Fees and Services			125
Part IV
Item 15.			Exhibits, Financial Statement Schedules			126
Item 16.			Form 10-K Summary			133
Signatures						134

DEFINED TERMS
The following is a list of frequently used abbreviations or acronyms that are found in this report:
NiSource Subsidiaries and Affiliates (not exhaustive)
Columbia of Kentucky						Columbia Gas of Kentucky, Inc.
Columbia of Maryland						Columbia Gas of Maryland, Inc.
Columbia of Ohio						Columbia Gas of Ohio, Inc.
Columbia of Pennsylvania						Columbia Gas of Pennsylvania, Inc.
Columbia of Virginia						Columbia Gas of Virginia, Inc.
NIPSCO						Northern Indiana Public Service Company LLC
NIPSCO Holdings I						NIPSCO Holdings I LLC
NIPSCO Holdings II						NIPSCO Holdings II LLC
NIPSCO Generation						NIPSCO Generation LLC
NiSource ("we," "us" or "our")						NiSource Inc.
Rosewater						Rosewater Wind Generation LLC and its wholly owned subsidiary, Rosewater Wind Farm LLC
Indiana Crossroads Solar						Indiana Crossroads Solar Generation LLC and its wholly owned subsidiary, Meadow Lake Solar Park LLC
Indiana Crossroads Wind						Indiana Crossroads Wind Generation LLC and its wholly owned subsidiary, Indiana Crossroads Wind Farm LLC
Dunns Bridge I						Dunns Bridge I Solar Generation LLC and its wholly owned subsidiary, Dunns Bridge Solar Center LLC
Dunns Bridge II						Dunns Bridge II Solar Generation LLC
Gibson						Gibson Solar Generation LLC
Fairbanks						Fairbanks Solar Generation LLC
Cavalry						Cavalry Solar Generation LLC
Abbreviations and Other
AFUDC						Allowance for funds used during construction
AOCI						Accumulated Other Comprehensive Income (Loss)
ASC						Accounting Standards Codification
ASU						Accounting Standards Update
ATM						At-the-market
BIP						BIP Blue Buyer L.L.C
BIP Blue Buyer VCOC L.L.C						BIP Blue Buyer VCOC L.L.C., a Delaware limited liability company and also an affiliate of Blackstone
Blackstone						Blackstone Infrastructure Partners L.P.
BTA						Build-transfer agreement
CCGT						Combined Cycle Gas Turbine
CCRs						Coal Combustion Residuals
CEO						Chief Executive Officer
CEP						Capital Expenditure Program
CERCLA						Comprehensive Environmental Response Compensation and Liability Act (also known as Superfund)
CFO						Chief Financial Officer
CISA						Certified Information Systems Auditor
CISO						Chief Information Security Officer
CISSP						Certified Information Systems Security Professional
CODM						Chief Operating Decision Maker

DEFINED TERMS
Columbia Operations						Reportable segment comprised of the results of NiSource Gas Distribution company, including all of its Columbia Gas distribution companies and related subsidiaries
Corporate Units						Series A Corporate Units
CPCN						Certificate of Public Convenience and Necessity
CRISC						Certified in Risk and Information Systems Control
DSIC						Distribution System Improvement Charge
DSM						Demand Side Management
EPA						United States Environmental Protection Agency
EPS						Earnings per share
Equity Units						Series A Equity Units
FAC						Fuel adjustment clause
FASB						Financial Accounting Standards Board
FERC						Federal Energy Regulatory Commission
FMCA						Federally Mandated Cost Adjustment
GAAP						Generally Accepted Accounting Principles
GCA						Gas cost adjustment
GCT						Generation Cost Tracker
GHG						Greenhouse gases
GWh						Gigawatt hours
HLBV						Hypothetical Liquidation at Book Value
IIJA						Infrastructure Investment and Jobs Act
IRA						Inflation Reduction Act
IRP						Infrastructure Replacement Program
IRS						Internal Revenue Service
IURC						Indiana Utility Regulatory Commission
JV						Joint Venture
LDCs						Local distribution companies
LIFO						Last-in, first-out
LIHEAP						Low Income Heating Energy Assistance Programs
Massachusetts Business						All of the assets sold to, and liabilities assumed by, Eversource pursuant to the Asset Purchase Agreement
MGP						Manufactured Gas Plant
MISO						Midcontinent Independent System Operator
MMDth						Million dekatherms
MW						Megawatts
MWh						Megawatt hours
NERC CIP						North American Electric Reliability Corporation Critical Infrastructure Protection
NIPSCO Electric						The electric generation and transmission activities of the NIPSCO Operations reportable segment
NIPSCO Gas						The gas distribution activities of the NIPSCO Operations reportable segment
NIPSCO Minority Interest Transaction						A transaction between NiSource, NIPSCO Holdings II (sole owner of NIPSCO) and an affiliate of Blackstone pursuant to a purchase and sale agreement entered into on June 17, 2023, that offered equity interests in NIPSCO Holdings II in exchange for capital contributions by the parties.

DEFINED TERMS
NIPSCO Operations						Reportable segment comprised of the results of NIPSCO Holdings I, NIPSCO Holdings II, and NIPSCO and all related subsidiaries
NYMEX						The New York Mercantile Exchange
OPEB						Other Postretirement and Postemployment Benefits
OT						Operational Technology
PCB						Polychlorinated biphenyls
PHMSA						Pipeline and Hazardous Materials Safety Administration
PPA						Power Purchase Agreement
PSC						Public Service Commission
PUCO						Public Utilities Commission of Ohio
ROE						Return on Equity
RNG						Renewable Natural Gas
ROU						Right of Use
SAVE						Steps to Advance Virginia's Energy Plan
Scope 1 GHG Emissions						Direct emissions from sources owned or controlled by us (e.g., emissions from our combustion of fuel, vehicles, and process emissions and fugitive emissions)
Scope 2 GHG Emissions						Indirect emissions from sources owned or controlled by us
SEC						Securities and Exchange Commission
SMRP						Safety Modification and Replacement Program
SMS						Safety Management System
STRIDE						Strategic Infrastructure Development and Enhancement
TCJA						An Act to provide for reconciliation pursuant to titles II and V of the concurrent resolution on the budget for fiscal year 2018 (commonly known as the Tax Cuts and Jobs Act of 2017)
TDSIC						Transmission, Distribution and Storage System Improvement Charge
TSA						Transportation Security Administration
VIE						Variable Interest Entity
WAM						Work and Asset Management enterprise resourcing system

Note regarding forward-looking statements

This Annual Report on Form 10-K contains "forward-looking statements," within the meaning of Section 27A of the Securities Act of 1933, as amended (the "Securities Act"), and Section 21E of the Securities Exchange Act of 1934, as amended (the "Exchange Act"). Investors and prospective investors should understand that many factors govern whether any forward-looking statement contained herein will be or can be realized. Any one of those factors could cause actual results to differ materially from those projected. These forward-looking statements include, but are not limited to, statements concerning our plans, strategies, objectives, expected performance, expenditures, recovery of expenditures through rates, stated on either a consolidated or segment basis, and any and all underlying assumptions and other statements that are other than statements of historical fact. Expressions of future goals and expectations and similar expressions, including "may," "will," "should," "could," "would," "aims," "seeks," "expects," "plans," "anticipates," "intends," "believes," "estimates," "predicts," "potential," "targets," "forecast," and "continue," reflecting something other than historical fact are intended to identify forward-looking statements. All forward-looking statements are based on assumptions that management believes to be reasonable; however, there can be no assurance that actual results will not differ materially.

Factors that could cause actual results to differ materially from the projections, forecasts, estimates and expectations discussed in this Annual Report on Form 10-K include, among other things:

• our ability to execute our business plan or growth strategy, including utility infrastructure investments, or business opportunities, such as data center development and related generation sources and transmission capabilities to meet potential load growth;

• our ability to manage data center growth in our service territories;

• potential incidents and other operating risks associated with our business;

• our ability to work successfully with our third-party investors;

• our ability to adapt to, and manage costs related to, advances in technology, including alternative energy sources and changes in laws and regulations;

• our increased dependency on technology;

• impacts related to our aging infrastructure;

• our ability to obtain sufficient insurance coverage and whether such coverage will protect us against significant losses;

• the success of our electric generation strategy;

• construction risks and supply risks;

• fluctuations in demand from residential and commercial customers;

• fluctuations in the price of energy commodities and related transportation costs or an inability to obtain an adequate, reliable and cost-effective fuel supply to meet customer demand;

• our ability to attract, retain or re-skill a qualified, diverse workforce and maintain good labor relations;

• our ability to manage new initiatives and organizational changes;

• the performance and quality of third-party suppliers and service providers;

• our ability to manage the financial and operational risks related to achieving our carbon emission reduction goals, including our Net Zero Goal (as defined below), including any future associated impact from business opportunities such as data center development as those opportunities evolve;

• potential cybersecurity attacks or security breaches;

• increased requirements and costs related to cybersecurity;

• the actions of activist stockholders;

• any damage to our reputation;

• the impacts of natural disasters, potential terrorist attacks or other catastrophic events;

• the physical impacts of climate change and the transition to a lower carbon future;

• our debt obligations;

• any changes to our credit rating or the credit rating of certain of our subsidiaries;

• adverse economic and capital market conditions, including increases in inflation or interest rates, recession, or changes in investor sentiment;

• economic regulation and the impact of regulatory rate reviews;

• our ability to obtain expected financial or regulatory outcomes;

• economic conditions in certain industries;

• the reliability of customers and suppliers to fulfill their payment and contractual obligations;

• the ability of our subsidiaries to generate cash;

• pension funding obligations;

• potential impairments of goodwill;

• the outcome of legal and regulatory proceedings, investigations, incidents, claims and litigation;

• compliance with changes in, or new interpretations of applicable laws, regulations and tariffs;

• the cost of compliance with environmental laws and regulations and the costs of associated liabilities;

• changes in tax laws or the interpretation thereof;

• and other matters set forth in Item 1, "Business," Item 1A, "Risk Factors" and Part II, Item 7, "Management’s Discussion and Analysis of Financial Condition and Results of Operations," of this report, some of which risks are beyond our control.

In addition, the relative contributions to profitability by each business segment, and the assumptions underlying the forward-looking statements relating thereto, may change over time.

All forward-looking statements are expressly qualified in their entirety by the foregoing cautionary statements. We undertake no obligation to, and expressly disclaim any such obligation to, update or revise any forward-looking statements to reflect changed assumptions, the occurrence of anticipated or unanticipated events or changes to the future results over time or otherwise, except as required by law.

PART I

ITEM 1. BUSINESS

NIS****OURCE INC.

Business

NiSource Inc. is an energy holding company under the Public Utility Holding Company Act of 2005 whose primary subsidiaries are fully regulated natural gas and electric utility companies, serving approximately 3.8 million customers in six states. NiSource is the successor to an Indiana corporation organized in 1987 under the name of NIPSCO Industries, Inc., which changed its name to NiSource Inc. on April 14, 1999.

NiSource’s principal subsidiaries include 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), and NIPSCO Holdings I (a holding company that owns a controlling interest in NIPSCO, a gas and electric utility). NiSource derives substantially all of its revenues and earnings from the operating results of these rate-regulated businesses.

Business Strategy

Our business strategy focuses on providing safe and reliable service through our core, rate-regulated, asset-based utilities, with the goal of adding value to all of our stakeholders. Our utilities continue to advance our core safety, infrastructure and environmental investment programs, supported by complementary regulatory and customer initiatives across the six states in which we operate. Our goal is to develop strategies that (i) support long-term infrastructure investment and safety programs to better serve our customers, (ii) align our tariff structures with our cost structure, and (iii) drive value and enable growth in an evolving energy ecosystem. These strategies focus on improving safety and reliability, enhancing customer experience, pursuing regulatory and legislative initiatives to increase accessibility for customers currently not on our gas and electric service, ensuring customer affordability and reducing emissions while generating sustainable returns.

We remain committed to the advancement of our SMS for the safety of our customers, communities and employees. Our SMS is the established operating model within NiSource. NiSource continues to maintain its certification to the American Petroleum Institute Recommended Practice 1173, which serves as the guiding practice for our SMS. In 2024, NiSource was recognized with the ISO 55001 certification from LRQA, one of the world’s leading providers of professional engineering and technology services. Achieving this international certification for asset management systems recognizes NiSource’s commitment to safety for our people, systems and customers. These certifications are important milestones for our SMS and NiSource’s ongoing journey towards operational excellence.

NiSource has two reportable segments: Columbia Operations and NIPSCO Operations. The remainder of our operations, which are not significant enough on a stand-alone basis to warrant treatment as an operating segment, consist of our centralized corporate activities and are primarily comprised of interest expense on holding company debt and unallocated corporate costs and activities. The following is a summary of the business for each reporting segment. Refer to Item 7, “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and Note 21, "Business Segment Information," in the Notes to Consolidated Financial Statements for additional information related to each segment.

Columbia Operations

Columbia Operations provides natural gas to approximately 2.4 million residential, commercial and industrial customers in Ohio, Pennsylvania, Virginia, Kentucky, and Maryland. We operate approximately 37,200 miles of distribution main pipeline plus the associated individual customer service lines and 330 miles of transmission main pipeline located in our service areas described above. Throughout our service areas we also have gate stations and other operations support facilities. See below for information on our owned operating facilities. There were no significant disruptions to our system or facilities during 2024.

Facility Name						Location			Type			Storage Capacity (MCF)
Blackhawk Underground Storage(1)						Beaver Falls, PA			Natural Gas			1,700,000
Eagle Cove Propane						Petersburgh, VA			Propane Gas			863
South Wales Propane						Jeffersonton, VA			Propane Gas			863
Portsmouth Propane-Air						Portsmouth, VA			Propane-Air Gas			17,300
Total Capacity												1,719,026

(1)NiSource has entered into an agreement to sell this facility, subject to approval by the Pennsylvania Public Utility Commission.

ITEM 1. BUSINESS

NIS****OURCE INC.

Competition. Due to open access and the deregulation of natural gas supplies, our LDC customers can purchase gas directly from producers and marketers in an open, competitive market. Certain of our subsidiaries are involved in programs that provide our residential and commercial customers the opportunity to purchase their natural gas requirements from third parties and use our subsidiaries for transportation services. As of December 31, 2024, 33.9% of our residential customers and 41.2% of our commercial customers participated in such programs.

We compete with (i) investor-owned, municipal, and cooperative electric utilities throughout our service areas, (ii) other regulated and unregulated natural gas intra and interstate pipelines and (iii) other alternate fuels, such as propane and fuel oil. We continue to be a well-positioned competitor in the energy markets in which we operate due to customer preference for natural gas.

Additionally, we are subject to seasonal fluctuations in sales. Revenues from our gas distribution operations are more significant during the heating season, which is from October through May. Please refer to Part II, Item 7, "Management's Discussion and Analysis of Financial Condition and Results of Operations - Results and Discussion of Operations - Columbia Operations," for additional information.

NIPSCO Operations

NIPSCO Gas

NIPSCO Gas distributes natural gas to approximately 0.9 million customers in northern Indiana. We operate approximately 17,900 miles of distribution main pipeline plus the associated individual customer service lines and 690 miles of transmission main pipeline located in our northern Indiana service areas. Throughout northern Indiana, we also have gate stations and other operations support facilities. See below for information on our owned operating facilities. There were no significant disruptions to our system or facilities during 2024.

Facility Name						Location			Type			Storage Capacity (MCF)
Royal Center Underground Storage						Royal Center, IN			Natural Gas			7,240,000
Rolling Prairie LNG						Rolling Prairie, IN			Liquified Natural Gas			4,000,000
Total Capacities												11,240,000

Competition. Similar to the Columbia Operations segment, NIPSCO Gas also operates in an open and competitive market which allows retail customers to purchase gas directly from producers and marketers. As of December 31, 2024, 6.7% of our residential customers and 17.6% of our commercial customers participated in such programs.

We compete with (i) investor-owned, municipal, and cooperative electric utilities throughout our northern Indiana service area, (ii) other regulated and unregulated natural gas intra and interstate pipelines and (iii) other alternate fuels, such as propane and fuel oil.

Additionally, we are subject to seasonal fluctuations in sales. Revenues from our gas distribution operations are more significant during the heating season, which is from October through May. Please refer to Part II, Item 7, "Management's Discussion and Analysis of Financial Condition and Results of Operations - Results and Discussion of Operations - NIPSCO Operations," for additional information.

ITEM 1. BUSINESS

NIS****OURCE INC.

NIPSCO Electric

We generate, transmit and distribute electricity to approximately 0.5 million customers in 20 counties in the northern part of Indiana and also engage in wholesale electric and transmission transactions. Our transmission system, has voltages from 69,000 to 765,000 volts, and consists of approximately 3,000 circuit miles. We are interconnected with eight neighboring electric utilities. We operate 66 transmission and 250 distribution substations, and own approximately 311,300 poles. We own and operate generation assets as well as source power through PPAs. We continue to transition our generation portfolio from coal-fired generation to lower-emission sources. We currently have six owned renewable generation facilities in service: Rosewater, Indiana Crossroads Wind, Indiana Crossroads Solar, Dunns Bridge I Solar, Cavalry Solar and Storage and Dunns Bridge II Solar and Storage. Cavalry Solar and Storage went into service May 2024 and Dunns Bridge II Solar and Storage went into service in January 2025. As of December 31, 2024, we have multiple PPAs that provide 600 MW of capacity, with contracts expiring between 2038 and 2040. We also operate two hydro electric generation facilities, a CCGT, and two coal generation facilities. The R.M. Schahfer coal facility is scheduled to be retired by the end of 2025 and the Michigan City coal facility is scheduled to be retired by the end of 2028. Our generating facilities had no material unplanned interruptions during 2024. See below for information on our owned generating facilities:

Facility Name						Location			Fuel Type			Generating Capacity (MW)****(1)
R.M. Schahfer						Wheatfield, IN			Steam - Coal			722
Michigan City						Michigan City, IN			Steam - Coal			455
Sugar Creek(2)						West Terre Haute, IN			CCGT			578
R.M. Schahfer						Wheatfield, IN			Natural Gas			155
Oakdale						Carroll County, IN			Hydro			9
Norway						White County, IN			Hydro			7
Rosewater(3)						White County, IN			Wind			102
Indiana Crossroads Wind(3)						White County, IN			Wind			302
Dunns Bridge I(3)						Jasper County, IN			Solar			265
Indiana Crossroads Solar(3)						White County, IN			Solar			200
Cavalry Solar and Storage(4)						White County, IN			Solar and Storage			200
Dunns Bridge II(4)						Jasper County, IN			Solar and Storage			435
Total MW Capacity												3,430

(1)Represents current net generating capability of each fossil fuel and hydro generating facility. Nameplate capacity is listed for wind and solar generating facilities.

(2)Represents capacity as of December 31, 2024. Sugar Creek is expected to further increase capacity pending MISO approval in 2025.

(3)NIPSCO is the managing partner of these JVs. Refer to Note 4, "Noncontrolling Interests," in the Notes to Consolidated Financial Statements for more information.

(4)Cavalry Solar and Storage has installed battery storage capacity of 45MW over a four-hour duration. Dunns Bridge has installed battery storage capacity of 56MW over a four-hour duration.

NIPSCO's 2024 Integrated Resource Plan ("2024 Plan") was submitted to the IURC in December 2024. The 2024 Plan informs future generation investments required to ensure reliability for NIPSCO's customers and incorporated factors such as anticipated load growth from data centers and other economic development opportunities, new EPA emissions rules, and evolving MISO resource accreditation rules. The 2024 Plan maintains the retirement decisions and capacity additions identified in the 2018 and 2021 Integrated Resource Plans and calls for additional generation resources through 2029 to support capacity requirements. In addition, if significant new data center load is contracted, the 2024 Plan calls for additional gas-fired resources to support that additional capacity. Refer to Item 7, "Management's Discussion and Analysis of Financial Condition and Results of Operations” for further discussion of these plans.

ITEM 1. BUSINESS

NIS****OURCE INC.

NIPSCO participates in the MISO transmission service and wholesale energy market. MISO is a nonprofit organization created in compliance with FERC regulations to improve the flow of electricity in the regional marketplace and to enhance electric reliability. Additionally, MISO is responsible for managing energy markets, transmission constraints and the day-ahead, real-time, Financial Transmission Rights and ancillary markets. NIPSCO has transferred functional control of its electric transmission assets to MISO, and transmission service for NIPSCO occurs under the MISO Open Access Transmission Tariff. NIPSCO generating units are dispatched by MISO which takes into account economics, reliability of the MISO system and unit availability. During the year ended December 31, 2024, NIPSCO generating units, inclusive of its owned renewable generation facilities, were dispatched to meet 55.4% of its overall system load, and the remainder of the overall system load was procured through PPAs and the MISO market.

Competition. Our NIPSCO Electric utility generally has exclusive service areas under Indiana regulations and retail electric customers in Indiana do not have the ability to choose their electric supplier. NIPSCO faces non-utility competition from other energy sources, such as self-generation by large industrial customers and other distributed energy sources.

Our NIPSCO Operations are subject to seasonal fluctuations in sales. Revenues from electric operations are more significant during the cooling season, which is primarily from June through September. Please refer to Part II, Item 7, "Management's Discussion and Analysis of Financial Condition and Results of Operations - Results and Discussion of Operations - NIPSCO Operations," for additional information.

Regulatory

The regulatory landscape, at both the state and federal levels, continues to evolve, impacting the operations and financial results of our operating companies. Management continually seeks new ways to be more competitive and efficient in this environment, while keeping service and affordability for customers at the forefront. We believe we are, in all material respects, in compliance with such laws and regulations and do not expect future compliance requirements to have a material impact on our capital expenditures, earnings, or competitive position. While we continue to monitor existing and pending laws and regulations, the impact of regulatory changes cannot be predicted with certainty.

Rate Case Actions. The following table describes current rate case actions as applicable in each of our jurisdictions. See "Cost Recovery and Trackers" below for further detail on trackers.

(in millions)
Company			Approved ROE			Requested Incremental Revenue			Approved Incremental Revenue			Filing Date			Rates Effective
Approved Rates Cases
Columbia of Pennsylvania(1)			None specified			$	124.1		$	74.0		March 15, 2024			December 2024
Columbia of Maryland(1)			None specified			$	6.5		$	3.9		May 12, 2023			December 2023
Columbia of Kentucky			9.75		%	$	23.8		$	14.3		May 16, 2024			January 2025
Columbia of Virginia(2)			None specified			$	40.5		$	25.8		April 29, 2022			October 2022
Columbia of Ohio			9.60		%	$	221.4		$	68.3		June 30, 2021			March 2023
NIPSCO - Gas(3)			9.75		%	$	161.9		$	120.9		October 25, 2023			August 2024
NIPSCO - Electric(4)			9.80		%	$	291.8		$	261.9		September 19, 2022			August 2023
Pending Rate Cases
NIPSCO - Electric(5)			In process			$	368.7		In process			September 12, 2024			September 2025
Columbia of Virginia(6)			In process			$	37.2		In process			April 29, 2024			October 2024
Columbia of Maryland			In process			$	10.7		In process			September 24, 2024			April 2025

(1) No approved ROE is identified for this matter since the approved revenue increase is the result of a black box settlement under which parties agree upon the amount of increase.

(2)The approved rate case resulted in a black box settlement, representing a settlement to a specific revenue increase but not a specified ROE. The settlement provides use of a 9.70% ROE for future SAVE filings.

(3)New rates were implemented in 2 steps, with implementation of Step 1 rates effective in August 2024 and Step 2 rates to be effective no later than March 2025.

(4)New rates were implemented in 2 steps, with implementation of Step 1 rates in August 2023 and Step 2 rates effective in March 2024.

(5)On February 7, 2025, NIPSCO and certain intervening parties filed a Joint Stipulation and Settlement Agreement with the IURC reflecting an annual revenue increase of $257.0 million. New rates proposed to be implemented in 2 steps, with implementation of Step 1 rates effective no later than September 2025 and Step 2 rates to be effective no later than March 2026.

(6)Rates are effective on an as filed basis and subject to refund. Columbia of Virginia and certain intervening parties, filed a Joint Stipulation and Proposed Recommendation for settlement on December 5, 2024, for an annual revenue increase of $28.2 million, net of SAVE.

ITEM 1. BUSINESS

NIS****OURCE INC.

FERC. Our service company and operating companies are subject to varying degrees of regulation by the FERC. NiSource Corporate Services files a FERC Form 60 annual report with its financial information as a FERC jurisdictional centralized service company. NiSource also files an annual FERC Form 61 which contains a narrative description of the service company's functions during the prior calendar year.

As natural gas LDCs, Columbia of Maryland, Columbia of Ohio, Columbia of Pennsylvania, Columbia of Virginia, Columbia of Kentucky and NIPSCO have limited jurisdictional certificates to transport gas in their respective service territories and into interstate commerce.

As an electric company, NIPSCO has Market Based Rate authority and is a Transmission Owner subject to FERC jurisdiction. NIPSCO files the following reports annually:

• FERC Form 1, which is a comprehensive financial and operating report,

• FERC Form 566, which is a list of its 20 largest purchases of electricity over the past three years,

• FERC Form 715, which is its Annual Transmission Planning and Evaluation Report and the base case power flow data from the Eastern Interconnection Reliability Assessment Group Multiregional Modeling Working Group, which was used by NIPSCO for transmission planning and,

• FERC Form 730, which is NIPSCO’s Report of Transmission Investment Activity.

As a Transmission Owner subject to the MISO Transmission Owners Agreement and Tariff, NIPSCO has various FERC jurisdictional obligations such as maintaining its Attachment O formula rates and corresponding protocols. NIPSCO also has FERC approvals to make affiliate transactions between itself and various JVs. NIPSCO’s officers, on the electric side, are also subject to FERC’s interlocking directorate rules and reporting requirements.

Regulatory Framework. The gas distribution activities of our Columbia and NIPSCO Operations have pursued non-traditional revenue sources within the evolving natural gas marketplace. These efforts include (i) gas supply cost incentive mechanisms for service to their core markets, and (ii) the sale of on-system services in the companies’ service territories. The on-system services are offered by us to customers and include products such as the transportation and balancing of gas on the gas distribution operations utility's system. The incentive mechanisms give the gas distribution operations utilities an opportunity to share in the savings created from such situations as gas purchases made below an agreed upon benchmark price and the remarketing of unused pipeline capacity to reduce overall pipeline costs.

We recognize that energy efficiency reduces emissions, conserves natural resources and saves our customers money. Our gas distribution companies offer programs such as energy efficiency upgrades, home checkups and weatherization services. The increased efficiency of natural gas appliances and improvements in home building codes and standards contribute to a long-term trend of declining average use per customer. While we are looking to expand offerings so the energy efficiency programs can benefit as many customers as possible, our gas distribution operations utilities have pursued changes in rate design to more effectively match recoveries with costs incurred. Columbia of Ohio has adopted a straight fixed variable rate design for residential and small commercial customers that closely links the recovery of fixed costs with fixed charges. Columbia of Maryland and Columbia of Virginia have regulatory approval for weather and revenue normalization adjustments for certain customer classes, which adjust monthly revenues that exceed or fall short of approved levels. Columbia of Pennsylvania continues to operate its pilot residential weather normalization adjustment and also has a fixed customer charge. This weather normalization adjustment only adjusts revenues when actual weather compared to normal varies by more than 3%. Columbia of Kentucky incorporates a weather normalization adjustment for certain customer classes and also has a fixed customer charge. NIPSCO Gas and Electric include a fixed customer charge for residential and small commercial and industrial customer classes. NIPSCO Gas has also received approval and implemented a weather normalization adjustment for certain of its customer classes.

While increased efficiency of electric appliances and improvements in home building codes and standards have similarly impacted the average use per electric customer in recent years, NIPSCO expects future growth in per customer usage as a result of increasing electric applications, such as electric vehicles. These ongoing changes in use of electricity will likely lead to development of innovative rate designs, and NIPSCO will continue efforts to design rates that increase the certainty of recovery of fixed costs.

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Cost Recovery and Trackers. Comparability of our operating results is impacted by regulatory trackers that allow for the recovery in rates of certain costs. Certain approved regulatory tracker mechanisms allow for abbreviated regulatory proceedings in order for the operating companies to quickly implement revised rates and recover associated costs.

A portion of the NIPSCO Operations' and Columbia Operations' gas distribution revenue is related to the recovery of gas costs through GCA's, the review of which occurs through standard regulatory proceedings. All states in our operating area require periodic review of actual gas procurement activity to determine prudence and confirm the recovery of prudently incurred energy commodity costs supplied to customers.

A portion of the NIPSCO Operations' revenue is related to the recovery of fuel costs to generate power and the fuel costs related to purchased power. These costs are recovered through a FAC, which is updated quarterly to reflect actual costs incurred to supply electricity to customers.

Political Action

The NiSource Political Action Committee ("NiPAC") provides our employees a voice in the political process. NiPAC is a voluntary, employee driven and funded political action committee, and NiPAC makes bipartisan political contributions to local, state and federal candidates where permitted and in accordance with established guidelines. Consistent with our commitments and our approach to engagement, the NiPAC leadership committee members evaluate candidates for support on issues important to our business.

Environmental and Safety Matters

PHMSA Legislation and Regulations

To fulfill our vision of being a trusted energy provider, we follow safety practices required by regulations and we implement our Safety Management System ("SMS"). SMS serves as the framework to identify and reduce risks and ensure consistent safety processes, procedures and operations across the organization.

As directed by law in the Protecting Our Infrastructure of Pipelines and Enhancing Safety (PIPES) Act of 2020, PHMSA has revised, and continues to revise, the pipeline safety regulations focused on public safety and environmental hazard mitigation. Specific areas of focus for upcoming rulemaking include leak detection and repair criteria (the "LDAR" rule) and regulations that require operators to upgrade their existing low-pressure regulating stations with enhanced safeguards and update distribution integrity management plans, emergency response plans, and operation and maintenance plans (the Safety of Gas Distribution Pipelines, or "SGDP" rule).

In May 2023, PHMSA proposed regulatory revisions under the PIPES Act of 2020 to minimize methane emissions and improve public safety. Under the proposed revisions, our subsidiaries would be required to detect and repair an increased number of gas leaks, reduce the time to repair leaks, increase leak survey, and expand our existing advanced leak detection program. In January 2025, PHMSA submitted a final LDAR rule to the Federal Register and is currently suspended.

In September 2023, PHMSA proposed additional regulatory revisions under the PIPES Act of 2020 to enhance distribution system safety through equipment and procedural expectations in the form of the SGDP rule. Operators will be required to incorporate additional protections for low pressure distribution systems that prevent over-pressurization, amend construction procedures designed to minimize the risk of incidents caused by system over-pressurization, and update distribution integrity management programs to cover and prepare for over-pressurization incidents. PHMSA did not progress the SGDP rulemaking in 2024.

We continue to evaluate and monitor PHMSA legislation and regulations but cannot predict the impact of changing pipeline safety regulations on our business at this time.

Climate Change Issues

Physical Climate Risks. Increased frequency of severe and extreme weather events associated with climate change could materially impact our facilities, energy sales, and results of operations. We are unable to predict these events. However, we perform assessments of physical risk, including physical climate risk, to our business. More extreme and volatile temperatures, increased storm intensity and flooding, and more volatile precipitation leading to changes in lake and river levels are among the weather events that are most likely to impact our business. Efforts to mitigate these physical risks continue to be implemented.

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Transition Climate Risks and Opportunities**.** We actively engage with and monitor the impact that proposed legislative and regulatory programs related to GHG emissions would have on our business. Refer to Item 1A. Risk Factors, "Operational Risks," of this Annual Report on Form 10-K for further detail.

Regarding federal policies, we continue to monitor the status of climate change-related legislation and regulation, including the IIJA, IRA, and EPA's Waste Emissions Charge for Petroleum and Natural Gas systems. We have identified and pursued potential opportunities associated with the IIJA and the IRA that align with our strategy. These opportunities include tax incentives for renewable generation and storage projects, tax credit transferability and grant funding for grid resiliency, hydrogen hubs and leak detection. The new federal administration has signaled through executive actions a desire to roll-back several climate-related policies including funding for IIJA and IRA programs. We continue to evaluate and monitor how these changes will impact our business.

In May 2024, the EPA published final greenhouse gas standards and guidelines for fossil fuel-fired power plants. The rules are not expected to impact NIPSCO’s existing electric generation, but, depending on the outcome of ongoing litigation and potential future changes to the rules, may impose certain operational limitations on other existing and new electric generation. Through the 2024 NIPSCO IRP process, we assessed that cost to electric customers would be approximately $675 million greater due to these rules.

We also continue to monitor evolving state policies related to GHG emissions. The Climate Solutions Now Act of 2022 requires Maryland to reduce GHG emissions by 60% by 2031 (from 2006 levels), and it requires the state to reach net zero emissions by 2045. The Maryland Department of the Environment ("MDE") adopted a plan to achieve its 2031 goal and is required to adopt a plan for their 2045 net zero goal by 2030. The Act also enacts a state policy to move to broader electrification of both existing buildings and new construction. In December 2024, the Maryland Department of the Environment issued updated final Building Energy Performance Standards, which would require net zero direct greenhouse gas emissions from large buildings by 2040 with interim targets, or payments of an alternative compliance fee. Columbia of Maryland is advocating for compliance pathways that use RNG, hydrogen, new technologies and emissions offsets. Under an executive order, Maryland is also developing a Clean Heat Standard and a Zero-Emission Heating Equipment Standard that are intended to transition gas appliances to electric heat pumps. Separately, the PSC has also initiated a proceeding related to Near-Term, Priority Actions and Comprehensive, Long-Term Planning for Maryland's Gas Companies. Columbia of Maryland cannot predict the final impact of these policies on our business at this time.

Net Zero Goal. In November 2022, we announced a goal of net zero greenhouse gas emissions by 2040, covering both Scope 1 and Scope 2 GHG emissions ("Net Zero Goal"). Our Net Zero Goal builds on greenhouse gas emission reductions achieved to-date. We plan to achieve our Net Zero Goal primarily through the continuation and enhancement of existing programs, such as retiring and replacing coal-fired electric generation with low- or zero-emission electric generation, ongoing pipe replacement and modernization programs, and deployment of advanced leak-detection technologies. In addition, we plan to advance other low- or zero-emission energy resources and technologies, which may include hydrogen, renewable natural gas, long-duration storage, and/or deployment of carbon capture and utilization technologies, if and when these become technologically and economically feasible. Carbon offsets and renewable energy credits may also be used to support achievement of our Net Zero Goal. As of the end of 2023, we had reduced Scope 1 GHG emissions by approximately 72% from 2005 levels.

Our greenhouse gas emissions projections, including achieving a Net Zero Goal, are subject to various assumptions that involve risks and uncertainties, and did not include any assumptions related to data center development and associated load growth. We remain committed to our Net Zero Goal, however, certain of our interim goals may evolve as we assess and respond to business opportunities such as data centers. Achievement of our Net Zero Goal by 2040 will require supportive regulatory and legislative policies, favorable stakeholder environments and advancement of technologies that are not currently economically or technologically feasible to deploy at scale, as well as execution of our business plan. Otherwise, our actual results or ability to achieve our Net Zero Goal, including by 2040, may differ materially.

As discussed in Management's Discussion within "Results and Discussion of Operations - NIPSCO Operations," NIPSCO continues to execute its electric generation transition consistent with the preferred pathways identified in its 2018, 2021 and 2024 Integrated Resource Plans. Additionally, as discussed in Management's Discussion within "Executive Summary - Energy Transition" and "Liquidity and Capital Resources - Regulatory Capital Programs," our natural gas distribution companies are lowering methane emissions by replacing aging infrastructure, which also increases safety and reliability for customers and communities.

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Human Capital

Human Capital Management Governance and Organizational Practices. The Compensation and Human Capital Committee ("C&HC Committee") of our Board of Directors (the "Board") is primarily responsible for assisting the Board in overseeing our human capital management practices. The C&HC Committee reviews our human capital management function and programs. The review of related procedures, programs, policies and practices allows the committee to make recommendations to management with respect to equal employment opportunity, employee engagement, organizational health, and talent management.

Human Capital Goals and Objectives*.* We have aligned our human capital goals to achieve overall company strategic and operational objectives by driving an enhanced talent strategy, elevating support for front-line leaders, fostering a culture of rigor and accountability, and strengthening our human resource function. We aspire to be an employer of choice, in part, through embedding inclusion throughout the enterprise and creating an enviable employee experience.

Workforce Composition*.* As of December 31, 2024, we had 7,687 full-time and 59 part-time active employees (i.e., not interns, not on leave or disability). Of our total workforce, 32% were subject to collective bargaining agreements with various labor unions. These collective bargaining agreements were renegotiated in 2021 and 2023 and expire in 2026 and 2027, respectively.

We foster an enviable work environment where all employees are energized. In efforts to become an employer of choice, we have developed sourcing strategies to attract and retain the most qualified talent. Our executive leadership team is characterized by a diverse composition, with 75% representation from both people of color ("POC") and females. We have increased our overall population of females and POC in 2024.

In 2024, our Diversity of Slate process supported our talent acquisition team filling 1,565 roles with 831 external candidates. These external hires included 34% being filled with POC and 40% being filled with female candidates. These sourcing efforts led our organization across all businesses to make progress toward a workforce composition that embraces different perspectives.

Our employee resource groups (ERGs) serve to create a culture of inclusion through their engagement of all employees throughout the year. We continue to develop ERG leaders to equip employees with the necessary tools to further support our efforts for advancement and strengthen our inclusive workplace. A key area for us has been our implementation and development of programs to drive higher retention and engagement of our employees, focusing on inclusive leadership training for Directors and Managers in the organization. Our commitment is grounded in the core belief that our purpose extends far beyond our primary role as a utility company.

We are committed to providing equal employment opportunities in each of our companies to all employees and applicants without regard to race, color, religion, national origin or ancestry, veteran status, disability, gender, age, marital status, sexual orientation, gender identity, genetic information, or any protected group status as defined by law. The input provided by our increasingly diverse workforce will continue to strengthen our corporate culture as well as drive constructive changes within our company to improve our operational strategies, enhance the quality of the services we provide, and increase revenue.

Talent Attraction. To recruit and hire individuals with a variety of skills, talents, backgrounds and experiences, we value and cultivate relationships with community and diversity outreach partners. We also target job fairs, including those focused on people of color, veteran, and female candidates while also partnering with local colleges and universities to identify and recruit qualified applicants.

Similar to other companies, we have focused on creating a flexible, agile model for roles that can be performed in a more remote setting. Our hybrid model recognizes differing ways of working; onsite, hybrid and remote. Most of our workforce is onsite and our hybrid and remote roles provide different avenues of working and seeking talent across our footprint. Hybrid employees work in a NiSource facility at least twice a week. This in-office presence supports colleague connection, development, in-person mentoring, and broader team building.

Talent Development and Retention*.* We offer leadership development programs to enhance the behaviors and skills of our existing and future leaders. In 2024, we had participation from employees of all levels. We also offer extensive technical and non-technical employee development training programs.