NISOURCE INC.

We continually evaluate the availability of adequate financing to fund our ongoing business operations, working capital and core safety and infrastructure investment programs. Our financing is sourced through cash flow from operations, the issuance of debt and/or equity, and minority interest investments in NIPSCO Holdings II and Generation Holdings II. Equity issuances are primarily conducted through our ATM program. Additionally, we received proceeds from tax credit transfers associated with the monetization of credits of $22.4 million and $23.5 million for the years ended December 31, 2025 and 2024, respectively. External debt financing is provided primarily through the issuance of long-term debt, accounts receivable securitization programs and our $1.85 billion commercial paper program, which is backstopped by our committed revolving credit facility. In December 2025, we increased our revolving credit facility availability from $1.85 billion to $2.50 billion from third-party lenders. We believe these sources provide adequate capital to fund our operating activities and capital expenditures in 2026 and beyond.

As discussed above under “ADS Contract and Strategy,” the aggregate cost of the Contract Assets is currently estimated to be approximately $7 billion. We expect to finance the construction and development of these assets through a number of sources including but not limited to funds received under the ADS Contract, debt and equity financing raised by NiSource and capital contributions from affiliates of Blackstone to NIPSCO Holdings II and Generation Holdings II in connection with such Blackstone affiliates’ minority interest investments in those entities. For additional information on these minority interest investments, refer to Note 4, "Noncontrolling Interests," and Note 19, "Other Commitments and Contingencies - E. Other Matters," included herein. If we enter into additional data center contracts, we expect that we would need to develop additional generation assets to serve our new data center customers. In order to fund the development of these assets which may be significant, we would be required to obtain significant additional financing, for which we may consider other funding sources, structures, or partnerships such as JVs or off-balance sheet arrangements in the form of BTAs to support maintenance of our investment grade credit ratings.

Sources of financing activities for the current year are as follows:

Details of our 2024 ATM program activity are summarized below:

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

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

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

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

Details of our 2025 ATM program activity are summarized below:

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

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

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

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

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

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

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

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

•In November 2025, we completed the issuance and sale of $1.0 billion of 5.750% fixed-to-fixed reset rate junior subordinated notes maturing in 2056, which resulted in approximately $984.3 million of net proceeds after debt issuance costs.

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

See Note 4, "Noncontrolling Interests,", Note 6, "Equity," Note 7, "Short-Term Borrowings," and Note 8, "Long-Term Debt," in the Notes to the Consolidated Financial Statements for more information.

Operating Activities

Net cash from operating activities for the year ended December 31, 2025 was $2,362.3 million, an increase of $580.8 million from 2024. This increase in cash from operating activities was primarily attributable to higher net income, depreciation expense, deferred taxes, supplier refunds received in 2025 and decreases in current year exchange gas receivables in 2025 compared to 2024.

Investing Activities

Net cash used for investing activities for the year ended December 31, 2025 was $4,524.1 million, an increase of $1,311.1 million from 2024. The year over year increase in investing activities was primarily comprised of milestone payments to renewable generation asset developers for certain of our BTA projects, advanced deposits, and additional capital expenditures in 2025 compared to 2024.

Capital Expenditures. The table below reflects actual capital expenditures and certain other investing activities by segment for 2025.

(1)Certain amounts may subsequently be allocated out of Corporate and Other Maintenance Costs to the Columbia Operations and NIPSCO Operations segments when placed in service. This amount also includes $39.7 million related to data center generation assets.

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

In addition to these capital expenditures, we invested $70.5 million in cloud computing costs in 2025. We also made $373.8 million in advanced deposits for project costs to secure certain long lead equipment related to data center generation assets.

We expect to make capital investments totaling approximately $21.0 billion during the 2026-2030 period to support our base business (exclusive of investments relating to the ADS Contract), including capital investments to support our generation transition strategy, and to invest approximately $7.0 billion during that period to develop the Contract Assets in connection with the ADS Contract, as set forth in the table below. As discussed above, if we enter into additional data center contracts, we expect to make significant further capital investments in addition to those set forth in the table below, and/or to consider alternative financing structures such as JVs or off-balance sheet arrangements. The forecasted capital investments are subject to continuing review and adjustment. Actual capital investments may vary from these estimates.

Regulatory Capital Programs. We continue to upgrade and modernize our electric system to enhance safety and reliability by addressing aged infrastructure and deploying advanced grid technologies. We are also upgrading and modernizing our gas infrastructure to enhance safety and reliability by reducing leaks. An ancillary benefit of these programs is the reduction of GHG emissions. In 2025, we continued to move forward on core infrastructure investment programs supported by complementary regulatory and customer initiatives across five states of our operating area.

The following table describes the most recent vintage of our regulatory programs to recover infrastructure replacement and other federally mandated compliance investments:

(1)Programs do not include any costs already included in base rates.

(2)TDSIC – 7 was originally filed in May 2025 and refiled in July 2025, due to the electric rate case order. The refiling adjusted the capital in the tracker from $744.7 million to $315.6 million.

(3)Capital investment is based on a projected amount. The capital investment has not all been incurred to date and represents a forecasted average for the billing period.

Columbia of Ohio filed an application in December 2025. The application seeks to continue Columbia of Ohio's PHMSA IRP Rider for calendar year 2027. The request includes recovery of $404.3 million of capital to reconfirm maximum allowable operating pressure of transmission class pipe to meet federal rule requirements.

NIPSCO filed a Gas TDSIC Plan (2026 - 2030) in December 2025. The petition is seeking recovery of new or replacement projects undertaken for the purpose of safety, reliability, system modernization, or economic development. The request includes $764.7 million of estimated capital, including indirect costs and AFUDC.

Refer to Note 12, "Regulatory Matters," in the Notes to Consolidated Financial Statements for a further discussion of regulatory developments during 2025.

Financing Activities

Common Stock, Preferred Stock and Equity Unit Sale. Refer to Note 6, "Equity," in the Notes to Consolidated Financial Statements for information on common stock, preferred stock and equity units activity.

Short-term Debt. Refer to Note 7, "Short-Term Borrowings," in the Notes to Consolidated Financial Statements for information on short-term debt.

Long-term Debt. Refer to Note 8, "Long-Term Debt," in the Notes to Consolidated Financial Statements for information on long-term debt.

Non-controlling Interest. Refer to Note 4, "Noncontrolling Interests," in the Notes to Consolidated Financial Statements for more information.

Sources of Liquidity

The following table displays our liquidity position as of December 31, 2025 and 2024:

(1)Represents the lesser of the seasonal limit or maximum borrowings supportable by the underlying receivables.

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

Credit Ratings. The credit rating agencies periodically review our ratings, taking into account factors such as our capital structure and earnings profile. The following table includes our and NIPSCO's credit ratings and ratings outlook as of December 31, 2025.

A credit rating is not a recommendation to buy, sell or hold securities, and may be subject to revision or withdrawal at any time by the assigning rating organization.

Certain of our subsidiaries have agreements that contain “ratings triggers” that require increased collateral if our credit ratings or the credit ratings of certain of our subsidiaries are below investment grade. These agreements are primarily for insurance purposes and for the physical purchase or sale of power. As of December 31, 2025, a collateral requirement of approximately $150.2 million would be required in the event of a downgrade below investment grade. In addition to agreements with ratings triggers, there are other agreements that contain “adequate assurance” or “material adverse change” provisions that could necessitate additional credit support such as letters of credit and cash collateral to transact business.

Equity. Our authorized capital stock consists of 770,000,000 shares, $0.01 par value, of which 750,000,000 are common stock and 20,000,000 are preferred stock. As of December 31, 2025, 478,432,058 shares of common stock were outstanding and no shares of preferred stock were outstanding. For more information regarding our common and preferred stock, see Note 6, "Equity," in the Notes to Consolidated Financial Statements.

Contractual Obligations, Cash Requirements and Off-Balance Sheet Arrangements

We have certain contractual obligations requiring payments at specified periods. Our material cash requirements are detailed below. We intend to use funds from the liquidity sources referenced above to meet these cash requirements.

At December 31, 2025, we had$15,477.5 million in long-term debt, of which $19.7 million is current, and $736.0 million in short-term borrowings outstanding.

During 2026 and 2027, we expect to make cash payments of $809.5 million and $879.3 million, respectively, related to pipeline service obligations including demand for gas transportation, gasstorage and gas purchases, and $87.6 million and $10.4 million, respectively, for long lead time items related to plant equipment purchases.

Our expected payments include employer contributions to pension and other postretirement benefits plans expected to be made in 2026. Plan contributions beyond 2026 are dependent upon a number of factors, including actual returns on plan assets, which cannot be reliably estimated at this time. In 2026, we expect to make contributions of approximately $2.7 million to our pension plans and approximately $18.3 million to our postretirement medical and life plans. Refer to Note 16, "Pension and Other Postemployment Benefits," in the Notes to Consolidated Financial Statements for more information.

We cannot reasonably estimate the settlement amounts or timing of cash flows related to asset retirement obligations on the Consolidated Balance Sheets.

We have uncertain income tax positions for which we are unable to predict when the matters will be resolved. Refer to Note 15, "Income Taxes," in the Notes to Consolidated Financial Statements for more information.

NIPSCO has executed several PPAs to purchase 100% of the output from renewable generation facilities at a fixed price per MWh. NIPSCO has also executed several BTAs with developers to construct renewable generation facilities. See Note 19, "Other Commitments and Contingencies - A. Contractual Obligations," and Note 19, "Other Commitments and Contingencies - E. Other Matters," in the Notes to Consolidated Financial Statements for additional information.

In addition, we, along with certain of our subsidiaries, enter into various agreements providing financial or performance assurance to third parties on behalf of certain subsidiaries. Such agreements include guarantees and stand-by letters of credit.

Refer to Note 19, "Other Commitments and Contingencies," in the Notes to Consolidated Financial Statements for additional information regarding our contractual obligations over the next 5 years and thereafter and our off-balance sheet arrangements.