
(in millions)	Total		2024		2025		2026		2027		2028		After
Long-term debt (1)	$	10,955.0	$	—	$	1,260.0	$	—	$	1,090.0	$	1,055.0	$	7,550.0
Interest payments on long-term debt	6,017.8		431.1		431.1		418.5		399.1		349.0		3,989.0
Finance leases(2)	321.8		34.8		30.7		25.7		20.6		19.3		190.7
Operating leases(3)	39.7		9.6		5.9		5.4		4.6		3.2		11.0
Energy commodity contracts	153.9		114.7		39.2		—		—		—		—
Service obligations:
Pipeline service obligations	2,196.6		652.0		485.7		406.3		388.7		162.3		101.6
IT service obligations	161.8		83.6		57.2		16.7		4.3		—		—
Other liabilities(4)	98.3		62.8		5.8		5.2		5.2		5.2		14.1
Total contractual obligations	$	19,944.9	$	1,388.6	$	2,315.6	$	877.8	$	1,912.5	$	1,594.0	$	11,856.4

(3) Operating lease payments shown above are inclusive of interest totaling $5.6 million. Operating lease balances do not include obligations for possible fleet vehicle lease renewals beyond the initial lease term. While we have the ability to renew these leases beyond the initial term, we are not reasonably certain to do so as they are renewed month-to-month after the first year.

Purchase and Service Obligations. We have entered into various purchase and service agreements whereby we are contractually obligated to make certain minimum payments in future periods. Our purchase obligations are for the purchase of physical quantities of natural gas, electricity and coal. Our service agreements encompass a broad range of business support and maintenance functions which are generally described below.

Our subsidiaries have entered into various energy commodity contracts to purchase physical quantities of natural gas, electricity and coal. These amounts represent the minimum quantity of these commodities we are obligated to purchase at both fixed and variable prices. To the extent contractual purchase prices are variable, obligations disclosed in the table above are valued at market prices as of December 31, 2023.

NIPSCO has power purchase arrangements representing a total of 700 MW of wind power, with contracts expiring between 2024 and 2040. No minimum quantities are specified within these agreements due to the variability of electricity generation from wind, so no amounts related to these contracts are included in the table above. Upon early termination of one of these agreements by NIPSCO for any reason (other than material breach by the counterparties), NIPSCO may be required to pay a termination charge that could be material depending on the events giving rise to termination and the timing of the termination.

B. 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 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. At December 31, 2023 and 2022, we issued stand-by letters of credit of $9.9 million and $10.2 million, respectively, for the benefit of third parties.

We provide guarantees related to our future performance under BTAs for our renewable generation projects. At December 31, 2023 and 2022, our guarantees for multiple BTAs totaled $646.1 million and $841.6 million, respectively. The amount of each guaranty will decrease upon the substantial completion of the construction of the facilities. See “- E. Other Matters - Generation Transition,” below for more information.

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

FERC Investigation. In April 2022, NIPSCO was notified that the FERC Office of Enforcement (“OE”) was conducting an investigation of an industrial customer for allegedly manipulating the MISO Demand Response (“DR”) market. On January 4, 2024, FERC issued an Order approving a Stipulation and Consent Agreement (the "FERC Stipulation and Consent Agreement") which resolved the FERC OE investigation. Under the FERC Stipulation and Consent Agreement, neither NIPSCO nor the industrial customer admitted or denied any wrongdoing. Further, under the FERC Stipulation and Consent Agreement, the industrial customer is to disgorge $48.5 million and NIPSCO is to disgorge $7.7 million. The full amount of disgorgements will be returned to customers. NIPSCO has recovered more than 50% of its costs.

Other Claims and Proceedings. We are also party to certain 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.

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 the majority of environmental assessment and remediation costs and asset retirement costs, further described below, to be recoverable through rates. See Note 12, "Regulatory Matters," for additional detail.

As of December 31, 2023 and 2022, we had recorded a liability of $80.0 million and $86.5 million, respectively, to cover environmental remediation at various sites. This liability is included in "Other accruals" and "Other noncurrent liabilities" in the Consolidated Balance Sheets. 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. See Note 11, "Asset Retirement Obligations," for a discussion of all obligations, including those discussed below.

CERCLA. Our subsidiaries are potentially responsible parties at waste disposal sites under the 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 Consolidated Financial Statements.

MGP. We maintain a program to identify and investigate former MGP sites where Gas Distribution Operations subsidiaries or predecessors may have liability. The program has identified 53 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. No material changes to the estimated future remediation costs were noted as a result of the refresh completed as of June 30, 2023. Our total estimated liability related to the facilities subject to remediation was $73.7 million and $81.0 million at December 31, 2023 and 2022, respectively. The liability represents our best estimate of the probable cost to remediate the MGP sites. We believe that it is reasonably possible that remediation costs could vary by as much as $15.1 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.

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 certain BTAs is dependent on timely completion of construction and either payment of the required purchase price or successful execution by NIPSCO of an agreement with a tax equity partner. NIPSCO and the tax equity partner, for each respective BTA, are obligated to make cash contributions to the JV that acquires the project at the date construction is substantially complete. Certain agreements require NIPSCO to make partial payments upon the developer's completion of significant construction milestones. 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. On January 17, 2024, the IURC approved the full ownership of Cavalry and Dunns Bridge II which will allow those BTAs to be executed through direct ownership. On November 22, 2023, Gibson transitioned from a PPA to a BTA.

NIPSCO Minority Interest Transaction. On December 31, 2023, pursuant to the terms of the BIP Purchase Agreement and simultaneously with the closing of the NIPSCO Minority Interest Transaction, Blackstone, NIPSCO Holdings I NIPSCO Holdings II and NiSource entered into an Amended and Restated Limited Liability Company Agreement (the "LLC Agreement") of NIPSCO Holdings II. Specifically, under the terms of the LLC Agreement, Blackstone will provide up to $250 million in additional capital contributions over a three-year period after the closing, which the obligation is backed by an Equity Commitment Letter from an affiliate of Blackstone. Under the LLC Agreement, Blackstone is entitled to appoint two directors to the board of directors of NIPSCO Holdings II (the “Board”) so long as Blackstone (together with any approved affiliate) holds at least a 17.5% percentage interest (as defined in the LLC Agreement). In connection with the closing, Blackstone appointed two directors to the Board, such that the Board is now comprised of seven directors, two appointed by Blackstone and five appointed by NiSource. The LLC Agreement also contains certain investor protections, including, among other things, requiring Blackstone approval for Holdings II to take certain major actions. In addition, the LLC Agreement contains certain terms regarding transfer rights and other obligations applicable to both Blackstone and NiSource. The LLC Agreement establishes, among other things, governance rights, exit rights, requirements for additional capital contributions, mechanics for distributions, and other arrangements for Holdings II from and following the closing.

On January 31, 2024, BIP transferred a 4.5% equity interest in NIPSCO Holdings II to BIP Blue Buyer VCOC L.L.C., a Delaware limited liability company and also an affiliate of Blackstone. Effective upon the closing of this transfer, the members of NIPSCO Holdings II entered into a Second Amended and Restated Limited Liability Company Operating Agreement of NIPSCO Holdings II (the "Amended LLC Agreement"). The two affiliates of Blackstone must vote their equity holdings under the Amended LLC Agreement as one investor.