Regulatory Assets and Liabilities (Tables)

The following regulatory assets and liabilities are reflected on the consolidated balance sheets as of June 30, 2026 and December 31, 2025.


	(dollars in thousands)
	2026		2025
Regulatory Assets:
Premium and loss on reacquired debt(a)	$	26,416	$	20,173
Amortization on financing leases(b)	16,393		19,556
Outage costs(c)	59,834		46,781
Asset retirement obligations – Ashpond and other(l)	219,511		228,400

Depreciation expense - Plant Vogtle(d)	30,567		31,279
Depreciation expense - Plant Wansley(e)	305,570		316,106
Deferred charges related to Vogtle Units No. 3 and No. 4 training costs(f)	53,157		53,619
Interest rate options cost(g)	120,247		123,650
Deferral of effects on net margin – TA Smith Energy Facility(h)	115,923		118,896
Deferral of effects on net margin – BC Smith Energy Facility(p)	9,925		13,868
Inventory adjustments - TA Smith Energy Facility(q)	13,191		13,701
Accumulated retirement costs for other obligations(i)	19,305		5,479
Natural gas hedges(n)	15,176		—
Other regulatory assets(o)	31,916		32,351
Total Regulatory Assets	$	1,037,131	$	1,023,859
Regulatory Liabilities:

Deferral of effects on net margin – Hawk Road Energy Facility(h)	14,480		14,788

Major maintenance reserve(j)	132,304		109,028

Deferred debt service adder(k)	197,794		201,836
Asset retirement obligations – Nuclear(l)	328,857		245,133
Revenue deferral plan(m)	75,920		107,784
Other revenue deferral plan(s)	1,595		—
Natural gas hedges(n)	—		10,642
Deferral of direct pay nuclear production tax credits(r)	180,082		180,082
Other regulatory liabilities(o)	155		567
Total Regulatory Liabilities	$	931,187	$	869,860
Net Regulatory Assets	$	105,944	$	153,999

(a)Represents premiums paid, together with unamortized transaction costs related to reacquired debt that are being amortized over the lives of the refunding debt, which range up to 30 years.

(b)Represents the difference between expense recognized for rate-making purposes versus financial statement purposes related to finance lease payments and the aggregate of the amortization of the asset and interest on the obligation.

(c)Consists of both coal-fired maintenance and nuclear refueling outage costs. Coal-fired outage costs are amortized on a straight-line basis to expense over periods up to 60 months, depending on the operating cycle of each unit. Nuclear refueling outage costs are amortized on a straight-line basis to expense over the 18 or 24-month operating cycles of each unit.

(d)Prior to Nuclear Regulatory Commission (NRC) approval of a 20-year license extension for Plant Vogtle Units No. 1 and No. 2, we deferred the difference between Plant Vogtle depreciation expense based on the then 40-year operating license and depreciation expense assuming an expected 20-year license extension. Amortization commenced upon NRC approval of the license extension in 2009 and is being amortized over the remaining life of the units.

(e)Represents the deferral of accelerated depreciation associated with the early retirement of Plant Wansley, which occurred on August 31, 2022. Amortization commenced upon the retirement of Plant Wansley and will end no later than December 31, 2040.

(f)Deferred charges consist of training related costs, including interest and carrying costs of such training. Amortization commenced with the commercial operation date of each unit and is being amortized to expense over the life of the units.

(g)Deferral of premiums paid to purchase interest rate options used to hedge interest rates on certain borrowings, related carrying costs and other incidentals associated with construction of Vogtle Units No. 3 and No. 4. Amortization commenced in August 2023 after Vogtle Unit No. 3 was placed in service.

(h)Effects on net margin for TA Smith and Hawk Road Energy Facilities were deferred through the end of 2015 and are being amortized over the remaining life of each respective plant.

(i)Represents the deferral or accrual of retirement costs associated with long-lived assets for which there are no legal obligations to retire the assets.

(j)Represents collections for future major maintenance costs; revenues are recognized as major maintenance costs are incurred.

(k)Represents collections to fund certain debt payments made through 2025 which were in excess of amounts collected through depreciation expense; the deferred credits will be amortized over the remaining useful life of the plants. Amortization commenced in January 2026.

(l)Represents the difference in the timing of recognition of decommissioning costs for financial statement purposes versus rate making purposes, as well as the deferral of unrealized gains and losses of funds set aside for decommissioning.

(m)Deferred revenues under a rate management program that allowed for additional collections over a five-year period which began in 2018. These amounts are being amortized to income and applied to member billings, per each members' election, over the subsequent five-year period.

(n)Represents the deferral of unrealized gains or losses on natural gas contracts.

(o)The amortization periods for other regulatory assets range up to 28 years and the amortization periods of other regulatory liabilities range up to 1 year.

(p)Effects on net margin for the BC Smith Energy Facility that are expected to be deferred until November 2026 and will be amortized over the remaining life of the plant.

(q)Represents the write-down of inventory associated with the TA Smith acquisition. Amortization commenced on June 1, 2024 and will end no later than May 31, 2039.

(r)Represents deferral of direct pay 45U NPTCs recognized for fiscal years 2024 and 2025. Both fiscal years were recognized at December 31, 2025. These 45U NPTCs, remain subject to an IRS audit until the three-year IRS statute of limitations has passed and/or completion of an IRS audit for that year’s 45U NPTCs (an "Examination Period"). We will amortize these 45U NPTCs as credits to the Production expense line item within our consolidated statements of revenues and expenses after the lapse of the applicable Examination Period for that year’s 45U NPTCs, with an estimated amortization period end date of December 31, 2028 and December 31, 2029, for fiscal year 2024 and fiscal year 2025 tax credits, respectively. We expect to defer and amortize such 45U NPTCs claimed for fiscal years subsequent to 2024 and 2025 in a similar manner on a rolling three-year basis.

(s)Deferred revenues under an additional rate management program that allows for additional collections over a three-year period which began in March 2026. These amounts will be amortized to income and applied to member billings, per each members' election, over the subsequent three-year period.