#1NiSource® We exist to deliver safe, reliable energy that drives value to our customers SUPPLEMENTAL SLIDES 3Q 2023 RESULTS November 1, 2023 H#2FORWARD-LOOKING STATEMENTS This presentation 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"). Forward-looking statements in this presentation include, but are not limited to, statements regarding the purchase and sale agreement that NiSource's wholly-owned subsidiary, NIPSCO Holdings II LLC, entered into with BIP BLUE BUYER L.L.C., an affiliate of Blackstone Infrastructure Partners (the "Investor") on June 17, 2023 whereby Investor will acquire newly issued membership interests of NIPSCO Holdings II LLC which will represent a 19.9% ownership in NIPSCO Holdings II LLC at closing time (the "NIPSCO Minority Equity Interest Šale"); statements regarding the ability to complete the NIPSCO Minority Equity Interest Sale on the anticipated timeline or at all; statements concerning the anticipated benefits of the NIPSCO Minority Equity Interest Sale if completed; statements concerning the projected impact of the NIPSCO Minority Equity Interest Sales on our performance or opportunities; any statements regarding our expectations, beliefs, plans, objectives or prospects or future performance or financial condition as a result of or in connection with the NIPSCO Minority Equity Interest Sale; 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. 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. 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 presentation include, but are not limited to, risks and uncertainties relating to the timing and certainty of closing the NIPSCO Minority Equity Interest Sale, the ability to obtain Federal Energy Regulatory Commission approval necessary to complete the NIPSCO Minority Equity Interest Sale; the ability to achieve the anticipated benefits of the NIPSCO Minority Equity Interest Sale; the effects of transaction costs; the effects of the NIPSCO Minority Equity Interest Sale on industry, market, economic, political or regulatory conditions outside of NiSource's control; any disruption to NiSource's business from the NIPSCO Minority Equity Interest Sale, including the diversion of management time on NIPSCO Minority Equity Interest Sale-related issues, our ability to execute our business plan or growth strategy, including utility infrastructure investments; potential incidents and other operating risks associated with our business; our ability to adapt to, and manage costs related to, advances in, or failures of, 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 natural gas costs 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 demands; the attraction and retention of a qualified, diverse workforce and ability to maintain good labor relations; our ability to manage new initiatives and organizational changes; the actions of activist stockholders; the performance of third-party suppliers and service providers; potential cybersecurity attacks; increased requirements and costs related to cybersecurity; any damage to our reputation; any remaining liabilities or impact related to the sale of the Massachusetts Business; 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 ability to manage the financial and operational risks related to achieving our carbon emission reduction goals, including our Net Zero Goal; our debt obligations; any changes to our credit rating or the credit rating of certain of our subsidiaries; any adverse effects related to our equity units; adverse economic and capital market conditions or increases in interest rates; inflation; recessions; economic regulation and the impact of regulatory rate reviews; our ability to obtain expected financial or regulatory outcomes; continuing and potential future impacts from the COVID-19 pandemic; 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 obli tions; potent mpairments of goodwill; the outcome of legal and regulatory proceedings, investigations, incidents, claims and litigation; potential remaining liabilities related to the Greater Lawrence Incident; compliance with applicable laws, regulations and tariffs; compliance with environmental laws and the costs of associated liabilities; changes in taxation; 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 our Annual Report on Form 10-K for the fiscal year ended December 31, 2022 and matters set forth in our Quarterly Reports on Form 10-Q for the quarters ended March 31, 2023 and June 30, 2023, respectively, 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. Regulation G Disclosure Statement This presentation includes financial results and guidance for NiSource with respect to net operating earnings available to common shareholders, diluted earnings per share and funds from operations/debt, which are non-GAAP financial measures as defined by the Securities and Exchange Commission's Regulation G. The company includes these measures because management believes they permit investors to view the company's performance using the same tools that management uses and to better evaluate the company's ongoing business performance. With respect to such guidance, it should be noted that there will likely be a difference between these measures and their GAAP equivalents due to various factors, including, but not limited to, fluctuations in weather, the impact of asset sales and impairments, and other unusual or infrequent items included in GAAP results. The company is not able to estimate the impact of such factors on GAAP earnings and, as such, is not providing earnings guidance on a GAAP basis. In addition, the company is not able to provide a reconciliation of its non-GAAP net operating earnings guidance or its funds from operations/debt guidance to their GAAP equivalents without unreasonable efforts. inⓇ We exist to deliver safe, reliable energy that drives value to our customers NiSource | NYSE: NI | nisource.com | f 2#3#4KEY PRIORITIES 1) 2) 3) ● ● ● Resilient Financial Commitments Reiterating upper half of 2023 non-GAAP NOEPS1 of $1.54-$1.60 and initiating 2024 guidance of $1.68-1.72 Extending 6-8% annual non-GAAP NOEPS¹ growth to 2023-28 $16 billion 2024-2028 base plan capital expenditures support 8%-10% annual 2023-2028 rate base growth² 14-16% FFO/Debt³ annually through 2028 - Superior Regulatory & Stakeholder Foundation NIPSCO electric rate case order received and implemented in August NIPSCO gas rate case filed in October Columbia Gas of Maryland rate case order received in October Balance Sheet Flexibility NIPSCO minority interest transaction FERC approval received in October & on track to close by year-end Programmatic and Enduring Investment Plans Plus Upside Opportunities Driven by safety, reliability, regulation, decarbonization, modernization Diluted Net Operating Earnings Per Share (Non-GAAP) Core business rate base growth; select years may exceed range Funds from Operations / Debt (Non-GAAP) Note: For the GAAP Diluted Earnings Per Share and GAAP Net Cash Flows from Operating Activities/Debt and the reconciliation of GAAP to non-GAAP diluted earnings per share and GAAP Net Cash Flows from Operating Activities/Debt to non-GAAP FFO/Debt, see Schedules 1 (A & B) and 3 in the appendix to this presentation inⓇ We exist to deliver safe, reliable energy that drives value to our customers NiSource | NYSE: NI | nisource.com f 4#5#6#7#8#9#10#11#12#13#14#15#16#17#18#19#20#21#22#23#24#25#26#27#28#29#30#31