Renewable generation filings. In February 2025, NIPSCO filed a petition with the IURC to modify its February 2023 order that approved a power purchase agreement related to Templeton and allow for NIPSCO to fully own Templeton. The IURC issued an order in September 2025 approving the filed petition.

NIPSCO Electric rate case filing. In February 2025, NIPSCO and certain intervening parties filed a Joint Stipulation and Settlement Agreement with the IURC. The IURC issued an order in June 2025, approving the Settlement Agreement without modification. New rates were implemented in multiple steps beginning in July 2025 and will continue with the final step no later than March 2026.

Columbia of Pennsylvania rate case filing. In December 2025, the Pennsylvania Public Utility Commission issued a final order accepting in part, and denying in part, Columbia's exceptions to the recommended decision issued by the Administrative Law Judges. The final order approved the continuation of a pilot residential Weather Normalization Adjustment with a few modifications (most notably increasing the percentage range in which weather normalization is applied from 3% to 5% and an increase to the residential fixed customer charge to $20.15. Rates became effective in January 2026. Two parties have filed petitions for reconsideration on certain aspects of the final order and petitions for reconsideration are pending.

GenCo filing. In January 2025, GenCo, an indirect subsidiary of NiSource Inc., filed a declination of jurisdiction petition with the IURC related to the ownership, development, financing, construction and operation of generation facilities. This was an

administrative filing and is a step in NIPSCO’s effort to set up a framework to accommodate megaload customers, including data centers. A settlement agreement among GenCo, NIPSCO, and a coalition of NIPSCO's largest industrial customers was approved by the IURC in September 2025. In October 2025, the Indiana Office of the Utility Consumer Counselor ("OUCC") filed a limited Request for Rehearing with the IURC and the OUCC filed a Notice of Appeal of the IURC order approving the GenCo settlement, which was immediately stayed by the Court of Appeals to allow the IURC process to be completed. In November 2025, the IURC issued an order granting the OUCC’s limited request for rehearing, which was supported by NIPSCO and GenCo. In December 2025, all parties who originally appealed the IURC approval filed motions to dismiss their respective appeals.

NIPSCO Electric Special Contract and GenCo PPA filing. In November 2025, NIPSCO and GenCo filed an application with the IURC seeking approval of (i) a retail special contract for electric service between NIPSCO and ADS, (ii) a related power purchase agreement between NIPSCO and GenCo, and (iii) an alternative regulatory plan and associated accounting treatment. Testimony from the OUCC and intervenors was filed in January 2026. The OUCC and one other intervenor were generally supportive of approval of the special contract and GenCo PPA, while one intervenor sought certain modifications to the special contract. A hearing is scheduled for February 2026. An order is anticipated in the second quarter of 2026.

202(c) Emergency Order for R.M. Schahfer coal facility. In December 2025, before the planned retirement of the R.M. Schahfer coal facility, the U.S. Secretary of Energy issued an emergency order under section 202(c) of the Federal Power Act requiring R.M. Schahfer to continue operating for 90 days, through March 23, 2026. The order stated that continued operation of R.M. Schahfer was required to meet an energy emergency across MISO’s North and Central regions. Following receipt of the emergency order, NIPSCO filed a complaint at FERC seeking a modification of the MISO Tariff to establish a mechanism for recovery and allocation of the cost to comply with this order. NIPSCO made two filings with the IURC related to the emergency order. The first filing is to confirm accounting treatment of the current electric rate order, and the second is a filing for recovery of federally mandated expenses related to the emergency order, which will be utilized in the event that any costs of complying with the emergency order fall outside of the MISO Tariff recovery. The Michigan City coal facility is scheduled to be retired by the end of 2028.

IURC Investigation. In November 2025, the IURC initiated an investigation into the accuracy of NIPSCO’s gas meters. This investigation followed NIPSCO's disclosure of a latent issue with a small percentage of the meter indexes in NIPSCO's gas meters, which was discovered during roll-out of new AMI communications modules for gas meters. A procedural schedule has been established and a hearing is expected in July 2026.

Regulatory Assets and Liabilities. We follow the accounting and reporting requirements of ASC Topic 980, which provides that regulated entities account for and report assets and liabilities consistent with the economic effect of regulatory rate-making procedures when the rates established are designed to recover the costs of providing the regulated service and it is probable that such rates will be charged and collected from customers. Certain expenses and credits subject to utility regulation or rate determination normally reflected in income or expense are deferred on the balance sheet and are recognized in the income statement as the related amounts are included in customer rates and recovered from or refunded to customers. We assess the probability of collection for all of our regulatory assets each period. The offset to the regulatory liability associated with our renewable investments included in regulated rates is recorded in "Depreciation and amortization" on the Statements of Consolidated Income.


At December 31, (in millions)	2025		2024
Regulatory Assets
Unrecognized pension and other postretirement benefit costs (see Note 16)	$	433.1	$	485.3
Deferred pension and other postretirement benefit costs (see Note 16)	30.8		45.3
Environmental costs (see Note 19-D.)	42.0		42.8
Regulatory effects of accounting for income taxes (see Note 1-N. and Note 15)	190.8		172.0
Under-recovered gas and fuel costs (see Note 1-J.)	41.3		82.3
Depreciation	218.4		214.9

Post-in-service carrying charges	287.2		280.8



Safety activity costs	200.6		203.7
DSM programs	13.4		17.8
Retired coal generating stations	552.1		617.0
Losses on commodity price risk programs (See Note 13)	10.1		6.5
Deferred property taxes	79.4		75.9
Renewable energy investments	130.7		81.3
WAM system filing	33.5		21.5
Customer assistance programs	17.3		24.4
Uncollected future cost of removal	102.5		—
Other	116.2		105.8
Total Regulatory Assets	$	2,499.4	$	2,477.3
Less: Current Portion	274.2		319.9
Total Noncurrent Regulatory Assets	$	2,225.2	$	2,157.4


At December 31, (in millions)	2025		2024
Regulatory Liabilities
Over-recovered gas and fuel costs (see Note 1-J.)	$	50.6	$	21.4
Cost of removal (see Note 11)	454.5		482.8
Regulatory effects of accounting for income taxes (see Note 1-N. and Note 15)	869.3		827.0
Deferred pension and other postretirement benefit costs (see Note 16)	28.0		40.4
Gains on commodity price risk programs (See Note 13)	19.2		28.7
Customer assistance programs	10.6		9.4
Off-system sales sharing	21.8		21.4
Renewable energy investments (See Note 1-S. and Note 4)	139.4		77.0
Rate refunds	68.9		16.6
Other	111.1		57.0
Total Regulatory Liabilities	$	1,773.4	$	1,581.7
Less: Current Portion	260.1		150.5
Total Noncurrent Regulatory Liabilities	$	1,513.3	$	1,431.2

Regulatory assets, including under-recovered gas and fuel costs and depreciation, of approximately $499.3 million and $671.3 million as of December 31, 2025 and 2024, respectively, are not earning a return on investment. These costs are recovered over a remaining life of between 15 and 75 years.

Unrecognized pension and other postretirement benefit costs. Represents the deferred other comprehensive income or loss of the actuarial gains or losses and the prior service costs or credits that arise during the period but that are not immediately recognized as components of net periodic benefit costs by certain subsidiaries that will ultimately be recovered through base rates.

Deferred pension and other postretirement benefit costs. Primarily relates to the difference between defined benefit plan expense recorded by certain subsidiaries due to regulatory orders and the corresponding expense that would otherwise be recorded in accordance with GAAP. This balance is driven by Columbia of Ohio deferrals.

Environmental costs. Includes certain recoverable costs related to gas plant sites, disposal sites or other sites onto which material may have migrated. The recovery of these costs is to be addressed in future base rates, billing riders or tracking mechanisms of certain of our subsidiaries.

Under-recovered gas and fuel costs. Represents the difference between the costs of gas and fuel, as well as energy acquired through power purchase agreements, including NIPSCO's own renewable projects, and the recovery of such costs in revenue and is used to adjust future billings for such deferrals on a basis consistent with applicable state-approved tariff provisions. Recovery of these costs is achieved through tracking mechanisms.

Post-in-service carrying charges. Represents deferred debt-based carrying charges incurred on certain assets placed into service but not yet included in customer rates. The majority of this balance is driven by Columbia of Ohio's IRP and CEP deferrals.

Safety activity costs. Represents the difference between costs incurred by certain of our subsidiaries in eligible safety programs in compliance with PHMSA regulations in excess of those being recovered in rates. The majority of this balance is driven by Columbia of Ohio.

Retired coal generating stations. Represents the net book value of Units 7 and 8 of Bailly Generating Station that was retired during 2018 and the net book value of Units 14 and 15 of R.M. Schahfer Generating Station retired in 2021. These amounts are currently being amortized at a rate consistent with their inclusion in customer rates. The August 2023 NIPSCO electric rate case order extends the recovery of, and on, the net book value of the stations by the end of 2034 and implements a revenue credit for the retired units. The credit is based on the difference between the year-end value of Units 14 and 15 and the most recent value established in the last base rate case proceeding or credit compliance filing.

Losses on commodity price risk programs. Represents the unrealized losses related to certain of our subsidiary's commodity price risk programs. These programs help to protect against the volatility of commodity prices and these amounts are collected from customers through their inclusion in customer rates.

WAM system filing. Represents the deferral of certain costs, including depreciation and amortization incurred in connection with improvements to its information technology systems through the design, development, and implementation of a new WAM program for the scheduling, dispatch, and execution of work and the management of underlying assets.

Over-recovered gas and fuel costs. Represents the difference between the cost of gas and fuel, as well as energy acquired through power purchase agreements, including NIPSCO's own renewable projects and, the recovery of such costs in revenues and is the basis to adjust future billings for such refunds on a basis consistent with applicable state-approved tariff provisions. Refunding of these revenues is achieved through tracking mechanisms.

Regulatory effects of accounting for income taxes. Represents amounts owed to customers for deferred taxes collected at a higher rate than the current statutory rates and liabilities associated with accelerated tax deductions owed to customers. Balance includes excess deferred taxes recorded upon implementation of the TCJA in December 2017, net of amounts amortized through 2025 and federal tax credits generated by Cavalry, Dunn's Bridge II, Fairbanks, and Gibson solar facilities that are passed back to customers. For discussion of the regulatory impact of the NIPSCO Minority Interest Transaction on deferred taxes, see Note 15, "Income Taxes," for additional details.

Gains on commodity price risk programs. Represents the unrealized gains related to certain of our subsidiary's commodity price risk programs. These programs help to protect against the volatility of commodity prices, and these amounts are passed back to customers through their inclusion in customer rates.

Renewable energy investments. Represents the regulatory deferral of certain amounts representing the timing difference between the profit earned from the JVs and the amount included in regulated rates to recover our approved investments in consolidated JVs. The offset to the regulatory liability associated with our renewable investments is recorded in "Depreciation expense" on the Statements of Consolidated Comprehensive Income. Refer to Note 1, "Nature of Operations and Summary of Significant Accounting Policies - S. Noncontrolling Interest," Note 4, "Noncontrolling Interests," and Note 9, "Property, Plant and Equipment," for additional information.