Taxes (Tables)

3 Months Ended

Mar. 31, 2025

Income Tax Disclosure [Abstract]

Effective Tax Rate Reconciliation

The consolidated income tax provision differs from the amount computed by applying the statutory federal income tax rate to income before income taxes, as follows:

	MGE Energy								MGE
Three Months Ended March 31,	2025				2024				2025				2024
Statutory federal income tax rate		21.0		%		21.0		%		21.0		%		21.0		%
State income taxes, net of federal benefit		6.2				6.2				6.2				6.2
Amortized investment tax credits		(1.4	)			(2.2	)			(1.5	)			(2.4	)
Credit for electricity from renewable energy		(9.6	)			(10.2	)			(10.5	)			(11.2	)
AFUDC equity, net		(0.6	)			(0.6	)			(0.7	)			(0.7	)
Amortization of utility excess deferred tax - tax reform(a)		(2.6	)			(6.2	)			(2.8	)			(6.7	)
Other, net, individually insignificant		0.1				(0.3	)			0.1				(0.4	)
Effective income tax rate		13.1		%		7.7		%		11.8		%		5.8		%

(a)Included are impacts of the Tax Cut and Jobs Act of 2017 for the regulated utility for excess deferred taxes recognized using a normalization method of accounting in recognition of IRS rules that restrict the rate at which the excess deferred taxes may be returned to utility customers. For both the three months ended March 31, 2025 and 2024, MGE recognized $0.9 million. For the three months ended March 31, 2024, MGE recognized $1.0 million of deferred taxes not restricted by IRS normalization rules.