FOR ADDITIONAL INFORMATION (Form 8-K)

FOR ADDITIONAL INFORMATION

Media Investors

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NiSource announces third quarter results

•Reaffirming upper half of 2025 non-GAAP adjusted EPS guidance

•Introducing 2026 non-GAAP consolidated adjusted EPS guidance

•Extending base plan expected non-GAAP adjusted EPS annual growth guidance of 6%-8% to 2026-2030

•Introducing 2026-2033 consolidated non-GAAP adjusted EPS compound annual growth rate of 8%-9%

•Announcing consolidated capital expenditure plan of $28.0 billion, inclusive of ~$7.0 billion of capital investment related to data centers

MERRILLVILLE, Ind. - NiSource Inc. (NYSE: NI) today announced, on a GAAP basis, net income available to common shareholders for the three months ended September 30, 2025, of $94.7 million, or $0.20 of earnings per diluted share, compared to net income available to common shareholders of $85.7 million, or $0.19 of earnings per diluted share, for the same period of 2024. For the nine months ended September 30, 2025, on a GAAP basis, NiSource's net income available to common shareholders was $671.7 million, or $1.42 of earnings per diluted share, compared to net income available to common shareholders of $515.8 million, or $1.14 of earnings per diluted share, for the same period of 2024.

NiSource also reported third quarter 2025 non-GAAP adjusted net income available to common shareholders of $91.8 million, or $0.19 of adjusted earnings per share ("EPS"), compared to non-GAAP adjusted net income available to common shareholders of $89.9 million, or $0.20 of adjusted EPS, for the same period of 2024. For the nine months ended September 30, 2025, NiSource's non-GAAP adjusted net income available to common shareholders was $656.0 million, or $1.38 of adjusted EPS, compared to non-GAAP adjusted net income available to common shareholders of $567.4 million, or $1.26 of adjusted EPS, for the same period of 2024. Schedule 1 of this press release contains a complete reconciliation of GAAP measures to non-GAAP measures. **

NiSource is reaffirming the upper half of its 2025 non-GAAP adjusted EPS guidance of $1.85-$1.89. In 2026, non-GAAP consolidated adjusted EPS is expected to be in the range of $2.02-$2.07. NiSource is extending its base capital plan to 2030, with base plan non-GAAP adjusted EPS growth expected to be 6%-8% annually, driven by $21.0 billion in base plan capital expenditures and 8%-10% rate base growth from 2026 to 2030. The newly consolidated capital expenditure plan of $28.0 billion total is approximately $8.6 billion more than the prior five-year plan, fueled by nearly $7.0 billion in strategic data center investments. This marks a 45% increase and supports an expected consolidated non-GAAP adjusted EPS compound annual growth rate (CAGR) of 8%-9% for 2026 through 2033.

"This is an exciting moment for NiSource," said President and CEO Lloyd Yates. "With GenCo approved and our new data center agreement in place, we're advancing transformative growth

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while protecting customers from the costs of large-load development, reinforcing that customer affordability remains at the heart of our strategy.

"This project ensures growth pays for growth, energizes Indiana's economy, and strengthens our ability to deliver reliable service through a more resilient, future-ready grid.

"I want to thank our employees and contractors for their outstanding dedication," Yates added. "Their work continues to drive meaningful value for our customers, regulators, and shareholders. We're proud to lead the way in responsible growth, demonstrating how thoughtful stakeholder engagement and innovative regulatory structures can unlock transformative opportunities. We're proud to lead the way in advancing economic development while maintaining the integrity of our financial plan."

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**Non-GAAP Disclosure Statement