New Accounting Standards

12 Months Ended

Dec. 31, 2025

Accounting Standards Update and Change in Accounting Principle [Abstract]

New Accounting Pronouncements

New Accounting Standards - MGE Energy and MGE.

In December 2023, the Financial Accounting Standards Board issued authoritative guidance within the codification's Income Taxes topic, which expanded the disclosure requirements over effective tax rate reconciliations and income taxes paid. For public business entities, the authoritative guidance became effective for fiscal years beginning after December 15, 2024. MGE adopted the standard as of the effective date. See Footnote 10 for income tax disclosures.

In November 2024, the Financial Accounting Standards Board issued authoritative guidance within the codification's Income Statement - Reporting Comprehensive Income topic, which added disclosure requirements for the disaggregation of certain income statement expenses. The authoritative guidance will become effective for annual reporting periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027. MGE will adopt the standard as of the effective date. The adoption of this standard will not have a material impact on MGE Energy's and MGE's income, comprehensive income, financial position or cash flows.

In September 2025, the Financial Accounting Standards Board issued authoritative guidance within the codification’s Internal-Use Software topic, which amends certain aspects of the accounting for and disclosure of software costs. The authoritative guidance will become effective for annual reporting periods beginning after December 15, 2027, and interim periods within those annual reporting periods; early adoption is permitted as of the beginning of an annual reporting period. MGE will adopt the standard as of the effective date. The adoption of this standard is not expected to have a material impact on MGE Energy's and MGE’s financial statements.