Pension and Other Postretirement Plans

9 Months Ended

Sep. 30, 2025

Retirement Benefits [Abstract]

Pension and Other Postretirement Plans

Pension and Other Postretirement Plans - MGE Energy and MGE.

MGE maintains qualified and nonqualified pension plans, health care, and life insurance benefits and defined contribution 401(k) benefit plans for its employees and retirees.

The components of net periodic benefit cost, other than the service cost component, are recorded in "Other income, net" on the consolidated statements of income. The service cost component is recorded in "Other operations and maintenance" on the consolidated statements of income. MGE has regulatory treatment and recognizes regulatory assets or liabilities for timing differences between when net periodic benefit costs are recovered and when costs are recognized.

The following table presents the components of net periodic benefit costs recognized.

	Three Months Ended						Nine Months Ended
	September 30,						September 30,
(In thousands)	2025			2024			2025			2024
Pension Benefits
Components of net periodic benefit cost:
Service cost	$	653		$	769		$	1,959		$	2,308
Interest cost		4,285			4,280			12,854			12,839
Expected return on assets		(7,254	)		(7,149	)		(21,761	)		(21,448	)
Amortization of:
Actuarial loss		75			215			225			644
Net periodic benefit (credit) cost	$	(2,241	)	$	(1,885	)	$	(6,723	)	$	(5,657	)
Postretirement Benefits
Components of net periodic benefit cost:
Service cost	$	186		$	214		$	557		$	642
Interest cost		757			778			2,271			2,354
Expected return on assets		(678	)		(675	)		(2,036	)		(2,059	)
Settlement cost		—			288			—			288
Amortization of:
Transition obligation		1			1			2			2
Prior service credit		—			(234	)		—			(242	)
Actuarial loss (gain)		(161	)		774			(482	)		568
Net periodic benefit cost	$	105		$	1,146		$	312		$	1,553

As approved by the PSCW, MGE is allowed to defer differences between actual employee benefit plan costs and costs reflected in current rates. The deferred costs may be recovered or refunded in MGE's next rate filing. For the three months ended September 30, 2025, MGE did not recover any previously deferred pension and other postretirement costs. For the nine months ended September 30, 2025, MGE recovered $0.7 million. During the three and nine months ended September 30, 2024, MGE recovered $0.5 million and $3.1 million, respectively. These costs have not been reflected in the table above.