10-Q

United States SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the quarterly period ended: June 30, 2025 ☐ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the transition period from _______________ to _______________
Commission File No.	Name of Registrant, State of Incorporation, Address of Principal Executive Offices, and Telephone No.	IRS Employer Identification No.
000-49965	MGE Energy, Inc. (a Wisconsin Corporation) 133 South Blair Street Madison, Wisconsin 53788 (608) 252-7000 | mgeenergy.com	39-2040501
000-1125	Madison Gas and Electric Company (a Wisconsin Corporation) 133 South Blair Street Madison, Wisconsin 53788 (608) 252-7000 | mge.com	39-0444025

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading symbol(s)	Name of each exchange on which registered
Common Stock, $1 Par Value Per Share	MGEE	The NASDAQ Stock Market

Indicate by check mark whether the registrants (1) have filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrants were required to file such reports), and (2) have been subject to such filing requirements for the past 90 days:

MGE Energy, Inc. Yes ☒ No ☐ Madison Gas and Electric Company Yes ☒ No ☐

Indicate by check mark whether the registrants have submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrants were required to submit such files):

MGE Energy, Inc. Yes ☒ No ☐ Madison Gas and Electric Company Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See definitions of "large accelerated filer," "accelerated filer," "smaller reporting company," and "emerging growth company" in Rule 12b-2 of the Exchange Act.

	Large Accelerated Filer	Accelerated Filer	Non-accelerated Filer	Smaller Reporting Company	Emerging Growth Company
MGE Energy, Inc.	☒	☐	☐	☐	☐
Madison Gas and Electric Company	☐	☐	☒	☐	☐

If an emerging growth company, indicate by check mark if the registrants have elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.

MGE Energy, Inc.        ☐ Madison Gas and Electric Company ☐

Indicate by check mark whether the registrants are shell companies (as defined in Rule 12b-2 of the Exchange Act):

MGE Energy, Inc. Yes ☐  No ☒ Madison Gas and Electric Company Yes ☐  No ☒

Number of Shares Outstanding of Each Class of Common Stock as of July 31, 2025
MGE Energy, Inc.	Common stock, $1.00 par value, 36,541,849 shares outstanding.
Madison Gas and Electric Company	Common stock, $1.00 par value, 17,347,894 shares outstanding (all of which are owned beneficially and of record by MGE Energy, Inc.).

1

Table of Contents

PART I. FINANCIAL INFORMATION	3
Filing Format	3
Forward-Looking Statements	3
Where to Find More Information	3
Definitions, Abbreviations, and Acronyms Used in the Text and Notes of this Report	4
Item 1. Financial Statements.	6
MGE Energy, Inc.	6
Consolidated Statements of Income (unaudited)	6
Consolidated Statements of Cash Flows (unaudited)	7
Consolidated Balance Sheets (unaudited)	8
Consolidated Statements of Common Equity (unaudited)	9
Madison Gas and Electric Company	10
Consolidated Statements of Income (unaudited)	10
Consolidated Statements of Cash Flows (unaudited)	11
Consolidated Balance Sheets (unaudited)	12
Consolidated Statements of Equity (unaudited)	13
MGE Energy, Inc., and Madison Gas and Electric Company - Notes to Consolidated Financial Statements (unaudited)	14
1. Summary of Significant Accounting Policies.	14
2. New Accounting Standards.	15
3. Investment in ATC and ATC Holdco.	15
4. Taxes.	16
5. Pension and Other Postretirement Plans.	17
6. Equity and Financing Arrangements.	17
7. Share-Based Compensation.	18
8. Commitments and Contingencies.	18
9. Rate Matters.	21
10. Derivative and Hedging Instruments.	22
11. Fair Value of Financial Instruments.	24
12. Joint Plant Construction Project Ownership.	27
13. Revenue.	27
14. Segment Information.	28
Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations.	31
Item 3. Quantitative and Qualitative Disclosures About Market Risk.	46
Item 4. Controls and Procedures.	46
PART II. OTHER INFORMATION.	47
Item 1. Legal Proceedings.	47
Item 1A. Risk Factors.	47
Item 2. Unregistered Sales of Equity Securities and Use of Proceeds.	47
Item 3. Defaults Upon Senior Securities.	47
Item 4. Mine Safety Disclosures.	47
Item 5. Other Information.	47
Item 6. Exhibits.	48
Signatures - MGE Energy, Inc.	49
Signatures - Madison Gas and Electric Company	50

2

PART I. FINANCIAL INFORMATION.

Filing Format

This combined Form 10-Q is being filed separately by MGE Energy, Inc. (MGE Energy) and Madison Gas and Electric Company (MGE). MGE is a wholly owned subsidiary of MGE Energy and represents a majority of its assets, liabilities, revenues, expenses, and operations. Thus, all information contained in this report relates to, and is filed by, MGE Energy. Information that is specifically identified in this report as relating solely to MGE Energy, such as its financial statements and information relating to its nonregulated business, does not relate to, and is not filed by, MGE. MGE makes no representation as to that information. The terms "we" and "our," as used in this report, refer to MGE Energy and its consolidated subsidiaries, unless otherwise indicated.

Forward-Looking Statements

Certain matters discussed in this report include "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. All statements that are not statements of historical facts are, or may be deemed to be, forward-looking statements. Such forward-looking statements are based on historical performance and current expectations, estimates, forecasts and projections about our future financial results, goals, plans, commitments, strategies and objectives, particularly related to future load growth, revenues, expenses, capital expenditures and rate recovery, financial resources, regulatory matters, and the scope and expense associated with future environmental regulation. Such statements involve inherent risks, assumptions and uncertainties, known or unknown, including internal or external factors that could delay, divert or change any of them, that are difficult to predict, may be beyond our control and could cause our future financial results, goals, plans and objectives to differ materially from those expressed in, or implied by, the statements. Words such as "believe," "expect," "anticipate," "estimate," "could," "should," "intend," "will," "commit," "target," "plan," and other similar words, and words relating to goals, targets and projections, generally identify forward-looking statements. Both MGE Energy and MGE caution investors that these forward-looking statements are subject to known and unknown risks and uncertainties that may cause actual results to differ materially from those projected, expressed, or implied.

The factors that could cause actual results to differ materially from the forward-looking statements made by a registrant include (a) those factors discussed in the following sections of the registrants' 2024 Annual Report on Form 10-K: Item 1A. Risk Factors; Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations, as updated by Part I, Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations in this report; and Item 8. Financial Statements and Supplementary Data – Footnote 16, as updated by Part I, Item 1. Financial Statements – Footnote 8 in this report; and (b) other factors discussed herein and in other filings made by that registrant with the Securities and Exchange Commission (SEC).

Readers are cautioned not to place undue reliance on these forward-looking statements, which apply only as of the date of this report. MGE Energy and MGE undertake no obligation to publicly update or revise any forward-looking statement to reflect events or circumstances after the date of this report, whether as a result of new information, future events, changed circumstances or otherwise, except as required by law.

Where to Find More Information

We file annual reports on Form 10-K, quarterly reports on Form 10-Q and current reports on Form 8-K and other information with the SEC. The SEC maintains an internet site at www.sec.gov that contains reports, proxy and information statements, and other information regarding issuers that file electronically with the SEC.

MGE Energy maintains a website at mgeenergy.com, and MGE maintains a website at mge.com. Copies of the reports and other information that we file with the SEC may be obtained from our websites free of charge. Information contained on MGE Energy's and MGE's websites shall not be deemed incorporated into, or to be a part of, this report.

3

Definitions, Abbreviations, and Acronyms Used in the Text and Notes of this Report

Abbreviations, acronyms, and definitions used in the text and notes of this report are defined below.

MGE Energy and Subsidiaries:
CWDC	Central Wisconsin Development Corporation
MAGAEL	MAGAEL, LLC
MGE	Madison Gas and Electric Company
MGE Energy	MGE Energy, Inc.
MGE Power	MGE Power, LLC
MGE Power Elm Road	MGE Power Elm Road, LLC
MGE Power West Campus	MGE Power West Campus, LLC
MGE Services	MGE Services, LLC
MGE State Energy Services	MGE State Energy Services, LLC
MGE Transco	MGE Transco Investment, LLC
MGEE Transco	MGEE Transco, LLC
North Mendota	North Mendota Energy & Technology Park, LLC
Other Defined Terms:
2024 Annual Report on Form 10-K	MGE Energy's and MGE's Annual Report on Form 10-K for the year ended December 31, 2024
2021 Incentive Plan	MGE Energy's 2021 Long-Term Incentive Plan
AFUDC	Allowance for Funds Used During Construction
ATC	American Transmission Company LLC
ATC Holdco	ATC Holdco, LLC
Badger Hollow II	Badger Hollow II Solar Farm
Blount	Blount Station
BTA	Best technology available
CA	Certificate of Authority
CBP	U.S. Customs and Border Protection
CCR	Coal Combustion Residual
Codification	Financial Accounting Standards Board Accounting Standards Codification
Columbia	Columbia Energy Center
Cooling degree days (CDD)	Measure of the extent to which the average daily temperature is above 65 degrees Fahrenheit, which is considered an indicator of possible increased demand for energy to provide cooling
CWIP	Construction Work in Progress
Darien	Darien Solar Energy Center
Dth	Dekatherms, a quantity measure for natural gas
ELG	Effluent Limitations Guidelines
Elm Road Units	Elm Road Generating Station
EPA	United States Environmental Protection Agency
FERC	Federal Energy Regulatory Commission
FTR	Financial Transmission Rights
GHG	Greenhouse gas
Heating degree days (HDD)	Measure of the extent to which the average daily temperature is below 65 degrees Fahrenheit, which is considered an indicator of possible increased demand for energy to provide heating
High Noon	High Noon Solar Project
IRS	Internal Revenue Service
ITC	Investment Tax Credit
Koshkonong	Koshkonong Solar Energy Center
kWh	Kilowatt-hour, a measure of electric energy produced
MISO	Midcontinent Independent System Operator (a regional transmission organization)
MW	Megawatt, a measure of electric energy generating capacity
MWh	Megawatt-hour, a measure of electric energy produced
NAAQS	National Ambient Air Quality Standards
Nasdaq	The Nasdaq Stock Market
NOx	Nitrogen oxide
OBBBA	One Big Beautiful Bill Act
Paris	Paris Solar and Battery Park
PGA	Purchased Gas Adjustment clause, a regulatory mechanism used to reconcile natural gas costs recovered in rates to actual costs
PM	Particulate Matter

4

PSCW	Public Service Commission of Wisconsin
PTC	Production Tax Credit
ROE	Return on equity
SEC	Securities and Exchange Commission
SO2	Sulfur dioxide
Stock Plan	Direct Stock Purchase and Dividend Reinvestment Plan of MGE Energy
Sunnyside	Sunnyside Solar and Battery Project
Therm	Measure of quantity of heat used to measure gas supply
UFLPA	Uyghur Forced Labor Protection Act
VIE	Variable Interest Entity
WCCF	West Campus Cogeneration Facility
WDNR	Wisconsin Department of Natural Resources
WEPCO	Wisconsin Electric Power Company, a subsidiary of WEC Energy Group, Inc.
West Riverside	West Riverside Energy Center in Beloit, Wisconsin
Working capital	Current assets less current liabilities
WPDES	Wisconsin Pollutant Discharge Elimination System
WRO	Withhold Release Order
XBRL	eXtensible Business Reporting Language

5

Item 1. Financial Statements.

MGE Energy, Inc.

Consolidated Statements of Income (unaudited)

(In thousands, except per share amounts)

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2025			2024			2025			2024
Operating Revenues:
Electric revenues	$	129,527		$	120,597		$	255,016		$	236,764
Gas revenues		29,925			25,116			123,406			100,285
Total Operating Revenues		159,452			145,713			378,422			337,049
Operating Expenses:
Fuel for electric generation		16,292			11,237			33,861			23,941
Purchased power		5,562			8,850			9,940			18,292
Cost of gas sold		11,313			6,293			65,277			48,170
Other operations and maintenance		57,777			56,730			114,336			110,704
Depreciation and amortization		28,354			26,932			56,032			53,532
Other general taxes		5,931			5,936			11,888			11,930
Total Operating Expenses		125,229			115,978			291,334			266,569
Operating Income		34,223			29,735			87,088			70,480
Other income, net		3,707			3,856			6,311			7,737
Interest expense, net		(8,457	)		(8,325	)		(16,038	)		(16,329	)
Income before income taxes		29,473			25,266			77,361			61,888
Income tax provision		(2,975	)		(1,472	)		(9,271	)		(4,280	)
Net Income	$	26,498		$	23,794		$	68,090		$	57,608
Earnings Per Share of Common Stock
Basic	$	0.73		$	0.66		$	1.86		$	1.59
Diluted	$	0.72		$	0.66		$	1.86		$	1.59
Dividends per share of common stock	$	0.450		$	0.428		$	0.900		$	0.855
Weighted Average Shares Outstanding
Basic		36,540			36,176			36,526			36,173
Diluted		36,569			36,197			36,557			36,196

The accompanying notes are an integral part of the above unaudited consolidated financial statements.

6

MGE Energy, Inc.

Consolidated Statements of Cash Flows (unaudited)

(In thousands)

	Six Months Ended
	June 30,
	2025			2024
Operating Activities:
Net income	$	68,090		$	57,608
Items not affecting cash:
Depreciation and amortization		56,032			53,532
Deferred income taxes		2,578			(1,351	)
Provision for doubtful receivables		4,400			4,400
Employee benefit plan (credit) cost		(2,320	)		323
Equity earnings in investments		(6,241	)		(5,526	)
Other items		378			930
Changes in working capital items:
Current assets		13,446			22,086
Accounts payable		(13,491	)		(9,646	)
Other current liabilities		1,298			3,718
Dividends from investments		6,008			4,238
Cash contributions to pension and other postretirement plans		(3,800	)		(3,634	)
Other noncurrent items, net		7,575			3,756
Cash Provided by Operating Activities		133,953			130,434
Investing Activities:
Capital expenditures		(111,753	)		(111,622	)
Capital contributions to investments		(5,871	)		(3,159	)
Other		(630	)		1,272
Cash Used for Investing Activities		(118,254	)		(113,509	)
Financing Activities:
Issuance of common stock, net		3,750			—
Cash dividends paid on common stock		(32,872	)		(30,930	)
Repayments of long-term debt		(2,625	)		(2,556	)
Proceeds from short-term debt		5,500			21,800
Other		(812	)		(728	)
Cash Used for Financing Activities		(27,059	)		(12,414	)
Change in cash, cash equivalents, and restricted cash		(11,360	)		4,511
Cash, cash equivalents, and restricted cash at beginning of period		24,496			15,026
Cash, cash equivalents, and restricted cash at end of period	$	13,136		$	19,537
Supplemental disclosures of cash flow information:
Significant noncash investing activities:
Accrued capital expenditures	$	9,120		$	11,416

The accompanying notes are an integral part of the above unaudited consolidated financial statements.

7

MGE Energy, Inc.

Consolidated Balance Sheets (unaudited)

(In thousands)

	June 30,		December 31,
ASSETS	2025		2024
Current Assets:
Cash and cash equivalents	$	10,569	$	21,302
Accounts receivable, less reserves of $8,586 and $6,905, respectively		43,308		51,277
Other accounts receivable, less reserves of $2,042 and $2,124, respectively		10,239		10,067
Unbilled revenues		29,815		35,833
Materials and supplies, at average cost		37,958		36,187
Fuel for electric generation, at average cost		11,706		11,521
Stored natural gas, at average cost		16,543		19,937
Prepaid taxes		17,946		18,390
Regulatory assets - current		6,317		8,522
Other current assets		13,851		14,229
Total Current Assets		198,252		227,265
Regulatory assets		41,313		36,764
Pension and other postretirement benefit asset		138,063		132,264
Other deferred assets and other		18,505		26,285
Property, Plant, and Equipment:
Property, plant, and equipment, net		2,238,086		2,149,138
Construction work in progress		102,648		138,208
Total Property, Plant, and Equipment		2,340,734		2,287,346
Investments		123,670		118,035
Total Assets	$	2,860,537	$	2,827,959
LIABILITIES AND CAPITALIZATION
Current Liabilities:
Long-term debt due within one year	$	5,358	$	5,285
Short-term debt		5,500		—
Accounts payable		50,344		77,466
Accrued interest and taxes		10,048		11,558
Accrued payroll related items		13,696		15,870
Regulatory liabilities - current		15,812		7,966
Other current liabilities		9,079		7,418
Total Current Liabilities		109,837		125,563
Other Credits:
Deferred income taxes		316,017		316,397
Investment tax credit - deferred		49,702		44,988
Regulatory liabilities		164,177		163,336
Accrued pension and other postretirement benefits		50,583		50,155
Asset retirement obligations		73,739		69,132
Other deferred liabilities and other		65,235		64,553
Total Other Credits		719,453		708,561
Capitalization:
Common shareholders' equity		1,269,973		1,230,138
Long-term debt		761,274		763,697
Total Capitalization		2,031,247		1,993,835
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	$	2,860,537	$	2,827,959

The accompanying notes are an integral part of the above unaudited consolidated financial statements.

8

MGE Energy, Inc.

Consolidated Statements of Common Equity (unaudited)

(In thousands, except per share amounts)

										Accumulated
					Additional					Other
	Common Stock				Paid-in		Retained			Comprehensive
	Shares		Value		Capital		Earnings			Income/(Loss)		Total
Three Months Ended June 30, 2024
Beginning Balance		36,176	$	36,176	$	397,093	$	725,514		$	—	$	1,158,783
Net income								23,794					23,794
Common stock dividends declared    ($0.428 per share)								(15,470	)				(15,470	)
Equity-based compensation plans and other						521							521
Ending Balance - June 30, 2024		36,176	$	36,176	$	397,614	$	733,838		$	—	$	1,167,628
Three Months Ended June 30, 2025
Beginning Balance		36,537	$	36,537	$	433,079	$	789,297		$	—	$	1,258,913
Net income								26,498					26,498
Common stock dividends declared    ($0.450 per share)								(16,444	)				(16,444	)
Direct Stock Purchase and Dividend Reinvestment Plan	5		5			466							471
Equity-based compensation plans and other						535							535
Ending Balance - June 30, 2025		36,542	$	36,542	$	434,080	$	799,351		$	—	$	1,269,973
Six Months Ended June 30, 2024
Beginning Balance		36,163	$	36,163	$	396,750	$	707,160		$	—	$	1,140,073
Net income								57,608					57,608
Common stock dividends declared    ($0.855 per share)								(30,930	)				(30,930	)
Equity-based compensation plans and other		13		13		864							877
Ending Balance - June 30, 2024		36,176	$	36,176	$	397,614	$	733,838		$	—	$	1,167,628
Six Months Ended June 30, 2025
Beginning Balance		36,490	$	36,490	$	429,515	$	764,133		$	—	$	1,230,138
Net income								68,090					68,090
Common stock dividends declared    ($0.900 per share)								(32,872	)				(32,872	)
Direct Stock Purchase and Dividend Reinvestment Plan	41		41			3,709							3,750
Equity-based compensation plans and other	11		11			856							867
Ending Balance - June 30, 2025		36,542	$	36,542	$	434,080	$	799,351		$	—	$	1,269,973

The accompanying notes are an integral part of the above unaudited consolidated financial statements.

9

Madison Gas and Electric Company

Consolidated Statements of Income (unaudited)

(In thousands)

	Three Months Ended						Six Months Ended
	June 30,						June 30,
	2025			2024			2025			2024
Operating Revenues:
Electric revenues	$	129,527		$	120,597		$	255,016		$	236,764
Gas revenues		29,925			25,116			123,406			100,285
Total Operating Revenues		159,452			145,713			378,422			337,049
Operating Expenses:
Fuel for electric generation		16,292			11,237			33,861			23,941
Purchased power		5,562			8,850			9,940			18,292
Cost of gas sold		11,313			6,293			65,277			48,170
Other operations and maintenance		57,489			56,601			113,751			110,161
Depreciation and amortization		28,354			26,932			56,032			53,532
Other general taxes		5,931			5,936			11,888			11,930
Total Operating Expenses		124,941			115,849			290,749			266,026
Operating Income		34,511			29,864			87,673			71,023
Other income, net		747			1,134			363			2,242
Interest expense, net		(8,554	)		(8,433	)		(16,189	)		(16,509	)
Income before income taxes		26,704			22,565			71,847			56,756
Income tax provision		(2,229	)		(811	)		(7,569	)		(2,802	)
Net Income	$	24,475		$	21,754		$	64,278		$	53,954
Less: Net Income Attributable to Noncontrolling   Interest, net of tax		(5,714	)		(5,766	)		(11,313	)		(11,363	)
Net Income Attributable to MGE	$	18,761		$	15,988		$	52,965		$	42,591

The accompanying notes are an integral part of the above unaudited consolidated financial statements.

10

Madison Gas and Electric Company

Consolidated Statements of Cash Flows (unaudited)

(In thousands)

	Six Months Ended
	June 30,
	2025			2024
Operating Activities:
Net income	$	64,278		$	53,954
Items not affecting cash:
Depreciation and amortization		56,032			53,532
Deferred income taxes		1,785			(1,287	)
Provision for doubtful receivables		4,400			4,400
Employee benefit plan (credit) cost		(2,319	)		323
Other items		766			1,446
Changes in working capital items:
Current assets		13,448			22,098
Accounts payable		(13,533	)		(9,642	)
Other current liabilities		836			4,774
Cash contributions to pension and other postretirement plans		(3,800	)		(3,634	)
Other noncurrent items, net		6,095			2,465
Cash Provided by Operating Activities		127,988			128,429
Investing Activities:
Capital expenditures		(111,753	)		(111,622	)
Other		(765	)		(894	)
Cash Used for Investing Activities		(112,518	)		(112,516	)
Financing Activities:
Cash dividends paid to parent by MGE		(23,500	)		(24,000	)
Distributions to parent from noncontrolling interest		(8,000	)		(10,000	)
Repayments of long-term debt		(2,625	)		(2,556	)
Proceeds from short-term debt		5,500			21,800
Other		(812	)		(728	)
Cash Used for Financing Activities		(29,437	)		(15,484	)
Change in cash, cash equivalents, and restricted cash		(13,967	)		429
Cash, cash equivalents, and restricted cash at beginning of period		20,059			6,705
Cash, cash equivalents, and restricted cash at end of period	$	6,092		$	7,134
Supplemental disclosures of cash flow information:
Significant noncash investing activities:
Accrued capital expenditures	$	9,120		$	11,416

The accompanying notes are an integral part of the above unaudited consolidated financial statements.

11

Madison Gas and Electric Company

Consolidated Balance Sheets (unaudited)

(In thousands)

	June 30,		December 31,
ASSETS	2025		2024
Current Assets:
Cash and cash equivalents	$	3,525	$	16,865
Accounts receivable, less reserves of $8,586 and $6,905, respectively		43,308		51,277
Other accounts receivable, less reserves of $2,042 and $2,124, respectively		10,235		10,063
Unbilled revenues		29,815		35,833
Materials and supplies, at average cost		37,958		36,187
Fuel for electric generation, at average cost		11,706		11,521
Stored natural gas, at average cost		16,543		19,937
Prepaid taxes		17,938		18,359
Regulatory assets - current		6,317		8,522
Other current assets		14,336		14,740
Total Current Assets		191,681		223,304
Regulatory assets		41,313		36,764
Pension and other post retirement benefit asset		138,063		132,264
Other deferred assets and other		17,921		25,690
Property, Plant, and Equipment:
Property, plant, and equipment, net		2,238,114		2,149,165
Construction work in progress		102,648		138,208
Total Property, Plant, and Equipment		2,340,762		2,287,373
Total Assets	$	2,729,740	$	2,705,395
LIABILITIES AND CAPITALIZATION
Current Liabilities:
Long-term debt due within one year	$	5,358	$	5,285
Short-term debt		5,500		—
Accounts payable		50,288		77,453
Accrued interest and taxes		9,885		11,866
Accrued payroll related items		13,696		15,870
Regulatory liabilities - current		15,812		7,966
Other current liabilities		9,087		7,418
Total Current Liabilities		109,626		125,858
Other Credits:
Deferred income taxes		279,789		280,961
Investment tax credit - deferred		49,702		44,988
Regulatory liabilities		164,177		163,336
Accrued pension and other postretirement benefits		50,583		50,155
Asset retirement obligations		73,739		69,132
Other deferred liabilities and other		68,267		67,463
Total Other Credits		686,257		676,035
Capitalization:
Common shareholder's equity		1,018,884		989,419
Noncontrolling interest		153,699		150,386
Total Equity		1,172,583		1,139,805
Long-term debt		761,274		763,697
Total Capitalization		1,933,857		1,903,502
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	$	2,729,740	$	2,705,395

The accompanying notes are an integral part of the above unaudited consolidated financial statements.

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Madison Gas and Electric Company

Consolidated Statements of Equity (unaudited)

(In thousands)

										Accumulated
					Additional					Other		Non-
	Common Stock				Paid-in		Retained			Comprehensive		Controlling
	Shares		Value		Capital		Earnings			Income/(Loss)		Interest			Total
Three Months Ended June 30, 2024
Beginning balance		17,348	$	17,348	$	252,917	$	646,063		$	—	$	151,128		$	1,067,456
Net income								15,988					5,766			21,754
Cash dividends paid to parent by MGE								(10,000	)							(10,000	)
Distributions to parent from    noncontrolling interest													(6,000	)		(6,000	)
Ending Balance - June 30, 2024		17,348	$	17,348	$	252,917	$	652,051		$	—	$	150,894		$	1,073,210
Three Months Ended June 30, 2025
Beginning balance		17,348	$	17,348	$	283,667	$	709,108		$	—	$	151,985		$	1,162,108
Net income								18,761					5,714			24,475
Cash dividends paid to parent by MGE								(10,000	)							(10,000	)
Distributions to parent from    noncontrolling interest													(4,000	)		(4,000	)
Ending Balance - June 30, 2025		17,348	$	17,348	$	283,667	$	717,869		$	—	$	153,699		$	1,172,583
Six Months Ended June 30, 2024
Beginning balance		17,348	$	17,348	$	252,917	$	633,460		$	—	$	149,531		$	1,053,256
Net income								42,591					11,363			53,954
Cash dividends paid to parent by MGE								(24,000	)							(24,000	)
Distributions to parent from    noncontrolling interest													(10,000	)		(10,000	)
Ending Balance - June 30, 2024		17,348	$	17,348	$	252,917	$	652,051		$	—	$	150,894		$	1,073,210
Six Months Ended June 30, 2025
Beginning balance		17,348	$	17,348	$	283,667	$	688,404		$	—	$	150,386		$	1,139,805
Net income								52,965					11,313			64,278
Cash dividends paid to parent by MGE								(23,500	)							(23,500	)
Distributions to parent from    noncontrolling interest													(8,000	)		(8,000	)
Ending Balance - June 30, 2025		17,348	$	17,348	$	283,667	$	717,869		$	—	$	153,699		$	1,172,583

The accompanying notes are an integral part of the above unaudited consolidated financial statements.

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MGE Energy, Inc., and Madison Gas and Electric Company

Notes to Consolidated Financial Statements (unaudited)

June 30, 2025

1.Summary of Significant Accounting Policies – MGE Energy and MGE.

a.Basis of Presentation.

This report is a combined report of MGE Energy and MGE. References in this report to "MGE Energy" are to MGE Energy, Inc. and its subsidiaries. References in this report to "MGE" are to Madison Gas and Electric Company.

MGE Power Elm Road and MGE Power West Campus own electric generating assets and lease those assets to MGE. Both entities are variable interest entities (VIE) under applicable authoritative accounting guidance. MGE is considered the primary beneficiary of these entities as a result of contractual agreements. As a result, MGE has consolidated MGE Power Elm Road and MGE Power West Campus in its financial reports. See Footnote 3 of the Notes to the Consolidated Financial Statements under Item 8, Financial Statements and Supplementary Data, of MGE Energy's and MGE's 2024 Annual Report on Form 10-K (the 2024 Annual Report on Form 10-K).

The accompanying consolidated financial statements as of June 30, 2025, and during the three and six months ended June 30, 2025, as applicable, are unaudited but include all adjustments that MGE Energy and MGE management consider necessary for a fair statement of their respective financial statements. All adjustments are of a normal, recurring nature except as otherwise disclosed. The year-end consolidated balance sheet information was derived from the audited balance sheet appearing in the 2024 Annual Report on Form 10-K but does not include all disclosures required by accounting principles generally accepted in the United States of America. These notes should be read in conjunction with the financial statements and the notes thereto located on pages 53 through 99 of the 2024 Annual Report on Form 10-K.

b.Cash, Cash Equivalents, and Restricted Cash.

The following table presents the components of total cash, cash equivalents, and restricted cash on the consolidated balance sheets.

	MGE Energy				MGE
	June 30,		December 31,		June 30,		December 31,
(In thousands)	2025		2024		2025		2024
Cash and cash equivalents	$	10,569	$	21,302	$	3,525	$	16,865
Restricted cash		869		1,113		869		1,113
Receivable - margin account		1,698		2,081		1,698		2,081
Cash, cash equivalents, and restricted cash	$	13,136	$	24,496	$	6,092	$	20,059

Cash Equivalents

All highly liquid investments purchased with an original maturity of three months or less are considered to be cash equivalents.

Restricted Cash

MGE has certain cash accounts that are restricted to uses other than current operations and designated for a specific purpose. MGE's restricted cash accounts include cash held by trustees for certain employee benefits and cash deposits held by third parties. These are included in "Other current assets" on the consolidated balance sheets.

Receivable – Margin Account

Cash amounts held by counterparties as margin collateral for certain financial transactions are recorded as Receivable – margin account in "Other current assets" on the consolidated balance sheets. The costs being hedged are fuel for electric generation, purchased power, and cost of gas sold.

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c.Property, Plant, and Equipment.

Columbia.

An asset that will be retired in the near future and substantially in advance of its previously expected retirement date is subject to abandonment accounting. In the second quarter of 2021, the operator of Columbia received approval from Midcontinent Independent System Operator (MISO) to retire Columbia Units 1 and 2. The co-owners intend to retire Unit 1 and Unit 2 by the end of 2029. Final timing and retirement dates continue to be evaluated and depend upon operational and regulatory considerations, capacity needs and availability, and other factors impacting one or more of the Columbia co-owners. As of June 30, 2025, early retirement of Columbia Unit 1 and 2 was probable.

Our ownership share of Columbia assets was classified as plant to be retired within "Property, plant, and equipment, net" on the consolidated balance sheets contained in the 2024 Annual Report on Form 10-K. Assets for Columbia Unit 1 and Unit 2 are currently included in rate base, and MGE continues to depreciate them on a straight-line basis using the composite depreciation rates approved by the Public Service Commission of Wisconsin (PSCW) that include retirement dates of 2029 for both Units.

If it becomes probable that regulators will disallow full recovery or a return on the remaining net book value of a generating unit that is either abandoned or probable of being abandoned, an impairment loss would be required. An impairment loss would be recorded to the extent that the remaining net book value of the generating unit exceeds the present value of the amount expected to be recovered from ratepayers. No impairment was recorded as of June 30, 2025.

2.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 is effective for annual disclosures for fiscal years beginning after December 15, 2024. MGE has adopted 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.

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 financial statements.

3.Investment in ATC and ATC Holdco - MGE Energy and MGE.

ATC owns and operates electric transmission facilities primarily in Wisconsin. MGE received an interest in ATC when it, like other Wisconsin electric utilities, contributed its electric transmission facilities to ATC, as required by Wisconsin law. That interest is presently held by MGE Transco, a subsidiary of MGE Energy. ATC Holdco was formed by several members of ATC, including MGE Energy, to pursue electric transmission development and investments outside of Wisconsin. The ownership interest in ATC Holdco is held by MGEE Transco, a subsidiary of MGE Energy.

MGE Transco and MGEE Transco have accounted for their investments in ATC and ATC Holdco, respectively, under the equity method of accounting. Equity earnings from investments are recorded as "Other income" on the consolidated statements of income of MGE Energy. MGE Transco recorded the following amounts related to its investment in ATC:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In thousands)	2025		2024		2025		2024
Equity earnings from investment in ATC	$	3,066	$	2,748	$	6,056	$	5,470
Dividends received from ATC		2,345		2,132		5,632		4,238
Capital contributions to ATC		2,679		1,070		5,171		1,785

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In July 2025, MGE Transco made a $3.2 million capital contribution to ATC.

ATC's summarized financial data is as follows:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
(In thousands)	2025			2024			2025			2024
Operating revenues	$	241,227		$	218,222		$	476,156		$	430,150
Operating expenses		(117,564	)		(109,197	)		(234,309	)		(214,039	)
Other income, net		550			356			633			543
Interest expense, net		(43,254	)		(36,040	)		(82,447	)		(71,458	)
Earnings before members' income taxes	$	80,959		$	73,341		$	160,033		$	145,196

MGE receives transmission and other related services from ATC. During the three and six months ended June 30, 2025, MGE recorded $10.2 million and $20.4 million, respectively, for transmission service compared to $9.1 million and $18.2 million for the comparable periods in 2024. MGE also provides a variety of operational, maintenance, and project management work for ATC, which is reimbursed by ATC. As of June 30, 2025 and December 31, 2024, MGE had a receivable due from ATC of $0.5 million and $2.0 million, respectively. The receivable is primarily related to transmission interconnection activities at the Paris and Darien solar generation sites. MGE will be reimbursed for these costs after the new generation assets are placed into service.

4.Taxes - MGE Energy and MGE.

Effective Tax Rate.

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 June 30,	2025				2024				2025				2024
Statutory federal income tax rate		21.0		%		21.0		%		21.0		%		21.0		%
State income taxes, net of federal benefit		6.4				6.2				6.2				6.2
Amortized investment tax credits		(1.3	)			(2.4	)			(1.4	)			(2.6	)
Credit for electricity from renewable energy		(13.2	)			(11.7	)			(14.4	)			(12.9	)
AFUDC equity, net		(0.5	)			(0.7	)			(0.5	)			(0.7	)
Amortization of utility excess deferred tax - tax reform(a)		(2.5	)			(6.8	)			(2.7	)			(7.5	)
Other, net, individually insignificant		0.2				0.2				0.2				0.1
Effective income tax rate		10.1		%		5.8		%		8.4		%		3.6		%
	MGE Energy								MGE
Six Months Ended June 30,	2025				2024				2025				2024
Statutory federal income tax rate		21.0		%		21.0		%		21.0		%		21.0		%
State income taxes, net of federal benefit		6.3				6.2				6.2				6.2
Amortized investment tax credits		(1.3	)			(2.3	)			(1.5	)			(2.5	)
Credit for electricity from renewable energy		(11.0	)			(10.8	)			(11.9	)			(11.9	)
AFUDC equity, net		(0.6	)			(0.7	)			(0.6	)			(0.7	)
Amortization of utility excess deferred tax - tax reform(a)		(2.5	)			(6.4	)			(2.8	)			(7.0	)
Other, net, individually insignificant		0.1				(0.1	)			0.1				(0.2	)
Effective income tax rate		12.0		%		6.9		%		10.5		%		4.9		%

(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 June 30, 2025 and 2024, MGE recognized $0.9 million. For both the six months ended June 30, 2025 and 2024, MGE recognized $1.8 million. For the three and six months ended June 30, 2024, MGE recognized $1.0 million and $2.1 million, respectively, of deferred taxes not restricted by IRS normalization rules.

In 2024, MGE sold transfer-eligible tax credits generated in 2023 and 2024. MGE elects to account for the transferred tax credits under the framework of Accounting for Income Taxes. The sale of tax credits is presented in the operating activities section of the consolidated statements of cash flows consistent with the presentation of cash taxes paid. MGE includes any expected proceeds from the transfer of tax credits in the evaluation of realizability of deferred tax assets related to tax credits

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and records a valuation allowance for the difference between the tax value of the credits and the expected proceeds. The PSCW approved the deferral by MGE of any differential between tax credit transfer proceeds and the tax value of credits reflected in rates to its next rate case filing.

5.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						Six Months Ended
	June 30,						June 30,
(In thousands)	2025			2024			2025			2024
Pension Benefits
Components of net periodic benefit cost:
Service cost	$	655		$	780		$	1,306		$	1,539
Interest cost		4,313			4,315			8,569			8,559
Expected return on assets		(7,246	)		(7,148	)		(14,507	)		(14,299	)
Amortization of:
Actuarial loss		102			313			150			429
Net periodic benefit (credit) cost	$	(2,176	)	$	(1,740	)	$	(4,482	)	$	(3,772	)
Postretirement Benefits
Components of net periodic benefit cost:
Service cost	$	188		$	217		$	371		$	428
Interest cost		754			779			1,514			1,576
Expected return on assets		(634	)		(693	)		(1,358	)		(1,384	)
Amortization of:
Transition obligation		—			—			1			1
Prior service credit		—			(4	)		—			(8	)
Actuarial gain		(173	)		(129	)		(321	)		(206	)
Net periodic benefit cost	$	135		$	170		$	207		$	407

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. During the three and six months ended June 30, 2025, MGE recovered $0.1 million and $0.7 million, respectively, of pension and other postretirement costs previously deferred, compared to $1.2 million and $2.6 million for the same periods in 2024. These costs have not been reflected in the table above.

6.Equity and Financing Arrangements - MGE Energy.

a.Common Stock.

MGE Energy sells shares of its common stock through its Direct Stock Purchase and Dividend Reinvestment Plan (the Stock Plan). Those shares may be newly issued shares or shares that are purchased in the open market by an independent agent for participants in the Stock Plan. Effective May 2025, MGE Energy transitioned to utilizing open market purchases for all shares issued under the Stock Plan. Sales of newly issued shares under the Stock Plan are covered by a shelf registration statement that MGE Energy filed with the SEC. During the six months ended June 30, 2025, MGE Energy issued approximately 40,995 shares of common stock under the Stock Plan. The net proceeds from these issuances were approximately $3.8 million, which were used for general corporate purposes.

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b.Dilutive Shares Calculation.

As of June 30, 2025, 30,803 shares were included in the calculation of diluted earnings per share related to nonvested equity awards. See Footnote 7 for additional information on share-based compensation awards.

7.Share-Based Compensation - MGE Energy and MGE.

During the three and six months ended June 30, 2025, MGE recorded $0.5 million and $1.7 million, respectively, in compensation expense related to share-based compensation awards compared to $0.7 million and $1.9 million, respectively, for the comparable periods in 2024.

In the first quarter of 2025, MGE distributed cash payments of $2.0 million and 11,213 shares of common stock related to awards that were granted in 2022 under the 2021 Incentive Plan.

In March 2025, MGE granted 18,136 performance units and 26,398 restricted stock units under the 2021 Incentive Plan to eligible employees and non-employee directors.

Share-based compensation expense is recognized on a straight-line basis over the requisite service period. Awards classified as equity awards are measured based on their grant-date fair value. Awards classified as liability awards are recorded at fair value each reporting period. The performance units can be paid out in cash, shares of common stock, or a combination of cash and stock and are classified as a liability award. The restricted stock units will be paid out in shares of common stock, and therefore are classified as equity awards.

8.Commitments and Contingencies - MGE Energy and MGE.

a.Environmental.

In February 2021, MGE and the other co-owners of Columbia announced plans to retire Units 1 and 2 at that facility. Effects of the environmental compliance requirements discussed below will depend upon the final Columbia retirement dates approved and required compliance dates of applicable regulations in effect.

MGE Energy and MGE are subject to frequently changing local, state, and federal regulations concerning air quality, water quality, land use, threatened and endangered species, hazardous materials handling, and solid waste disposal. These regulations affect the manner in which operations are conducted, the costs of operations, as well as capital and operating expenditures. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Regulatory initiatives, proposed rules, and court challenges to adopted rules could potentially have a material effect on capital expenditures and operating costs. Management believes compliance costs will be recovered in future rates based on previous treatment of environmental compliance projects.

These initiatives, proposed rules, and court challenges include:

•The United States Environmental Protection Agency's (EPA) promulgated water Effluent Limitations Guidelines (ELG) and standards for steam electric power plants that focus on the reduction of metals and other pollutants in wastewater from new and existing power plants.

With the closure of the wet pond system in 2023 (as described in further detail in the CCR section below), Columbia complies with ELG requirements. With the installation of additional wastewater treatment equipment completed in 2023, the Elm Road Units comply with ELG requirements.

In May 2024, the EPA finalized the ELG rule that further regulates the wastewater discharges associated with coal-fired power plants. The rule focuses on wastewater discharges from flue gas desulfurization and bottom ash transport water. The rule includes a reduction in requirements for plants that have already installed pollution controls based on previous versions of the rule, and for plants that will be retiring or switching to natural gas by certain dates. Although the 2024 ELG rule is currently being challenged in federal court, the litigation is on hold while the EPA undertakes a reconsideration process. The 2024 rule builds upon the 2020 ELG Rule, which also remains under legal challenge and is similarly on hold pending the outcome of the EPA's review.

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Pollution control prevention equipment was installed under previous versions of the rule and the planned fuel switching to natural gas. MGE and the operator of the Elm Road Units are currently evaluating operational options and costs for Elm Road to be in compliance with the requirements of the rule.

•The EPA's cooling water intake rule requires cooling water intake structures at electric power plants to meet best technology available (BTA) standards to reduce the mortality from entrainment (drawing aquatic life into a plant's cooling system) and impingement (trapping aquatic life on screens of cooling water intake structures).

Blount received its most recent Wisconsin Pollutant Discharge Elimination System (WPDES) permit from the Wisconsin Department of Natural Resources (WDNR) in October 2023. Blount's latest WPDES permit assumes that the plant meets BTA standards for entrainment for the duration of this permit which expires in 2028. The WDNR included a requirement to conduct an optimization study to demonstrate compliance with impingement BTA standards in the latest permit that needs to be completed by January 2028. Once the WDNR determines the impingement requirements at Blount, MGE will be able to determine any compliance costs of meeting Blount's permit requirements.

Intakes at Columbia are subject to this rule. The Columbia operator timely submitted its renewal application. BTA improvements required by the renewal permit will be coordinated with the owners' plan to retire both units by the end of 2029. MGE will continue to work with Columbia's operator to evaluate regulatory requirements in light of the planned retirement. MGE does not expect this rule to have a material effect on Columbia.

•Greenhouse Gas (GHG) new source performance standards and emission guidelines were established under the Clean Air Act for states to use in developing plans to control GHG emissions from fossil fuel-fired electric generating units, including existing and proposed regulations governing existing, new, or modified fossil-fuel generating units.

In May 2024, the EPA published its final performance standards and emission guidelines under Section 111(b) of the Clean Air Act for carbon dioxide emissions from new combustion turbines and existing fossil fuel-fired boilers used to produce electricity. The final rule granted some emissions flexibility for existing coal-fired units that retire and/or fuel switch by certain dates. For existing natural gas boiler units, the final rule established a process where states must submit plans to the EPA for establishing standards. States had two years from the publication date of these rules to submit plans to the EPA for review and approval. Preliminary evaluation of the final ruling showed that MGE met the requirements for the gas-fired boilers at Blount. Furthermore, MGE would meet the requirements for the coal-fired units at Columbia through planned unit retirements and the Elm Road Units through its transition to natural gas. In June 2025, the EPA published a proposed rule with two potential options: (1) repeal the performance standards and emission guidelines under Section 111 of the Clean Air Act associated with GHG emissions from fossil fuel-fired power plants, or (2) retain only the efficiency-based requirements for new natural gas-fired power plants and repeal all other aspects of the rule. In July 2025, EPA released a new proposed rule titled “Reconsideration of 2009 Endangerment Finding and Greenhouse Gas Vehicle Standards”. This proposal would repeal EPA’s 2009 GHG Endangerment Finding, which in effect, would undo the basis for federal regulation of GHG under the Clean Air Act. MGE will continue to follow these rule developments.

•The EPA's rule to regulate ambient levels of ozone through the 2015 Ozone National Ambient Air Quality Standards (NAAQS).

The Elm Road Units are located in Milwaukee County, Wisconsin, a serious nonattainment area for the 2015 Ozone NAAQS. At this time, the operator of the Elm Road Units does not expect that the 2015 Ozone NAAQS or the Milwaukee County nonattainment designation will have a direct material effect on the Elm Road Units.

•The EPA's rule to regulate Fine Particulate Matter (PM2.5).

In March 2024, the EPA published a final rule to lower the average annual PM2.5 NAAQS from 12 ug/m3 to 9 ug/m3 effective May 2024. The new annual PM2.5 NAAQS could impact Milwaukee County, where the Elm Road units are located, if the county is determined to be in nonattainment. A nonattainment designation would require the State of Wisconsin to develop a plan to get into attainment, which would likely include additional limitations for new and modified plants in the county. In February 2025, Wisconsin's Governor Evers submitted a state-wide attainment recommendation to the EPA.

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The final impact of this rule will not be known until the EPA determines the attainment status of Wisconsin counties and the State of Wisconsin develops an attainment implementation plan for any areas not in attainment. MGE will continue to follow the rule's developments.

•Rules regulating nitrogen oxide (NOx) and sulfur dioxide (SO2) emissions, including the Good Neighbor Plan and Clean Air Visibility Rule.

The EPA's Good Neighbor Plan and its progeny are a suite of interstate air pollution transport rules designed to reduce ozone and PM2.5 ambient air levels in areas that the EPA has determined as being significantly impacted by pollution from upwind states. This is accomplished through a reduction in NOx and SO2 from qualifying fossil fuel-fired power plants and industrial boilers in upwind "contributing" states. NOx and SO2 contribute to fine particulate pollution and NOx contributes to ozone formation in downwind areas. Reductions are generally achieved through a cap-and-trade system. Individual plants can meet their caps through reducing emissions and/or buying allowances on the market.

In March 2023 (published June 2023), the EPA finalized its Federal Implementation Plan to address state obligations under the Clean Air Act "good neighbor" provisions for the 2015 Ozone NAAQS (Good Neighbor Plan). The Good Neighbor Plan impacts 23 states, including Wisconsin. For Wisconsin, the Good Neighbor Plan includes revisions to the current obligations for fossil-fuel power generation, which includes Blount, Columbia, the Elm Road Units, WCCF, West Riverside, and West Marinette. Emissions budgets can be met with planned retirements, fuel switching, and immediately available measures, including consistently operating emissions controls already installed at power plants. In 2026, additional obligations would go into effect, including a further reduction in emissions budgets. Wisconsin would need to submit a State Implementation Plan to meet its obligations or accept the EPA's Good Neighbor Plan.

Multiple legal challenges to the Good Neighbor Plan and related state implementation plan disapprovals are pending, including in the United States Court of Appeals for the District of Columbia. In June 2024, the Supreme Court of the United States granted a request to stay the Good Neighbor Plan and block its enforcement pending judicial review by the U.S. Court of Appeals for the District of Columbia on the merits of petitioner's challenges to implementation of the rule. The EPA has temporarily halted the enforcement of the Good Neighbor Plan's requirements for all pollution sources in states affected by the plan, including Wisconsin. While the EPA addresses these concerns, interim rules have been implemented in Wisconsin to address interstate pollution. Based on MGE's current evaluation, if the Good Neighbor Plan goes into effect as-is, the 2026 additional emission reductions may impact the Elm Road Units. However, final impact of the rules will not be known until judicial reviews are completed and/or the EPA takes further action regarding the rule.

•The EPA's Coal Combustion Residuals (CCR) Rule.

The CCR rule regulates the disposal of solid waste coal ash and defines what ash use activities would be considered generally exempt beneficial reuse of coal ash. The CCR rule also regulates landfills, ash ponds, and other surface impoundments used for coal combustion residuals by regulating their design, location, monitoring, and operation. The CCR rule requires owners and operators of coal-fired power plants to stop transporting CCR and non-CCR wastewater to unlined surface impoundments. At Columbia, the coal combustion residuals system completed in 2023 replaced the unlined surface impoundment, and Columbia complies with this rule.

Review of the Elm Road Units has indicated that the costs to comply with the CCR rule are not expected to be significant.

In May 2024, the EPA published its final CCR Legacy Rule. The CCR Legacy Rule applies to previously closed disposal sites. In 2024, MGE recorded an asset retirement obligation for its estimated share of the legal liability associated with the effect of the CCR Legacy Rule for remediation and groundwater compliance monitoring at Columbia. Actual costs of compliance may be different than the amount recorded due to potential changes in compliance strategies that will be used, as well as other potential changes in cost estimate.

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b.Legal Matters.

MGE is involved in various legal matters that are being defended and handled in the normal course of business. MGE accrues for costs that are probable of being incurred and subject to reasonable estimation. The accrued amount for these matters is not material to the financial statements. MGE does not expect the resolution of these matters to have a material adverse effect on its consolidated results of operations, financial condition, or cash flows.

c.Purchase Contracts.

MGE Energy and MGE have entered into various commodity supply, transportation, and storage contracts to meet their obligations to deliver electricity and natural gas to customers. Management expects to recover these costs in future customer rates. The following table shows future commitments related to purchase contracts as of June 30, 2025:

(In thousands)	2025		2026		2027		2028		2029		Thereafter
Coal(a)	$	9,437	$	8,387	$	4,043	$	4,126	$	—	$	—
Natural gas(b)		26,109		51,334		37,306		41,131		40,951		316,598
Renewable energy(c)		6,084		3,454		3,324		3,324		1,350		38,100
	$	41,630	$	63,175	$	44,673	$	48,581	$	42,301	$	354,698

(a)Total coal commitments for MGE's share of the Columbia and Elm Road Units, including transportation. Fuel procurement for MGE's jointly owned Columbia and Elm Road Units is handled by Wisconsin Power and Light Company and WEPCO, respectively, who are the operators of those facilities.

(b)MGE's natural gas transportation and storage contracts require fixed monthly payments for firm supply pipeline transportation and storage capacity. The pricing components of the fixed monthly payments for the transportation and storage contracts are approved by FERC but may be subject to change. MGE's natural gas supply commitments include market-based pricing.

(c)Operational commitments for solar and wind facilities.

9.Rate Matters - MGE Energy and MGE.

a.Rate Proceedings.

	Rate increase	Return on Common Equity	Common Equity Component of Regulatory Capital Structure	Effective Date
Approved 2024/2025 rate proceeding(a)(b)
Electric	1.54%	9.7%	56.1%	1/1/2024
Gas	2.44%	9.7%	56.1%	1/1/2024
Electric(c)	2.63%	9.7%	56.1%	1/1/2025
Gas	1.32%	9.7%	56.1%	1/1/2025
Proposed 2026/2027 rate proceeding(d)
Electric(e)	4.89%	10.0%	56.1%	1/1/2026
Gas(e)	2.33%	10.0%	56.1%	1/1/2026
Electric(f)	4.33%	10.0%	56.0%	1/1/2027
Gas(f)	2.16%	10.0%	56.0%	1/1/2027

(a)The electric rate increase was driven by an increase in rate base including our investments made in West Riverside, local solar, continued investment in grid modernization, as well as higher costs for transmission, pension and other post retirement benefits, and uncollectible costs (including costs previously deferred from prior years). This increase in electric costs is offset by a decrease in fuel costs and benefit from lower tax expense (including impacts from the Inflation Reduction Act). MGE filed an updated 2025 fuel forecast with the PSCW in 2024, which will impact rates in 2025, based on any variance between the forecast submitted as part of the rates and updated forecast. In addition, the PSCW authorized MGE to defer a recovery of and a return on costs associated for any change in the in-service date for Paris and force majeure costs for Badger Hollow II and Paris that were not reflected in this rate filing. The PSCW also approved deferral of any differential in PTC tax credits reflected in rates and actual credits produced. These deferrals will be reflected in MGE's next rate case filing. The gas rate increases were also driven by our investment made in grid modernization and higher pension and other post retirement benefits and uncollectible costs (including costs previously deferred from prior years). This increase in gas costs is offset by a tax benefit related to excess deferred taxes. Included in the gas residential rate is a reduction in the customer fixed charge.

(b)The 2024/2025 rate order includes an earnings sharing mechanism, under which, if MGE earns above the authorized Return on Equity (ROE) in the rate order: (i) the utility will retain 100.0% of earnings for the first 15 basis points above the authorized ROE; (ii) 50.0% of the next 60 basis points will be required to be deferred and returned to customers; and (iii) 100.0% of any remaining excess earnings will be required to be refunded to customers. The earnings calculation excludes fuel rules adjustments. See "Fuel Rules" below.

(c)The PSCW approved a 2025 Fuel Cost Plan in December 2024. The plan lowered the 2025 increase in electric rates to 2.63% to reflect lower expected fuel costs.

(d)In April 2025, MGE filed a proposed 2-year rate case and PSCW approval is pending. A final order is expected before the end of the year.

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(e)The proposed electric rate increase reflects growth in rate base, primarily from investments in Paris (battery), Darien (battery), Sunnyside (solar), West Riverside, and continued investment in grid modernization, as well as higher costs for transmission. The increase in electric costs is offset by a decrease in fuel costs, changes in pension and other post retirement benefits, and benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas increase is driven by an increase in rate base including continued distribution infrastructure improvements designed to enhance reliability and safety and system modernization. The increase in gas costs is offset by changes in pension and other post retirement benefits.

(f)The proposed electric rate increase is driven by an increase in rate base including investments made in the Koshkonong (solar), Sunnyside (battery), and High Noon (solar/battery) projects, and continued investment in grid modernization projects. The increase in electric costs is offset by a benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas rate increase is driven by an increase in rate base.

b.Fuel Rules.

Fuel rules require Wisconsin utilities to defer electric fuel-related costs that fall outside a symmetrical cost tolerance band around the amount approved for a utility in its annual fuel proceedings. Any over- or under-recovery of the actual costs is determined in the following year and is then reflected in future billings to electric retail customers. The fuel rules bandwidth is set at plus or minus 2% in 2025 and 2024. The electric fuel-related costs are subject to an excess revenues test. Excess revenues are defined as revenues in the year in question that provide MGE with a greater return on common equity than authorized by the PSCW in MGE's latest rate order. The recovery of under-collected electric fuel-related costs would be reduced by the amount that exceeds the excess revenue test. These costs are subject to the PSCW's annual review of fuel costs completed in the year following the deferral. The following table summarizes deferred electric fuel-related costs:

	Fuel Costs (Savings) (in millions)	Refund or Recovery Period
2022	$8.8(a)	October 2023 through September 2024
2023	($7.2)(a)	October 2024 through December 2024
2024	($3.0)(a)	October 2025
2025	($2.5)	(b)

(a)There was no change to the refund or recovery in the fuel rules proceedings from the amount MGE deferred.

(b)These costs will be subject to the PSCW's annual review of 2025 fuel costs, expected to be completed in 2026.

10.Derivative and Hedging Instruments - MGE Energy and MGE.

a.Purpose.

As part of its regular operations, MGE enters into contracts, including options, swaps, futures, forwards, and other contractual commitments, to manage its exposure to commodity prices. To the extent that these contracts are derivatives, MGE assesses whether or not the normal purchases or normal sales exclusion applies. For contracts to which this exclusion cannot be applied, the derivatives are recognized in the consolidated balance sheets at fair value. MGE's financial commodity derivative activities are conducted in accordance with its electric and gas risk management program, which is approved by the PSCW and limits the volume MGE can hedge with specific risk management strategies. The maximum length of time over which cash flows related to energy commodities can be hedged is four years. If the derivative qualifies for regulatory deferral, the derivatives are marked to fair value and are offset with a corresponding regulatory asset or liability depending on whether the derivative is in a net loss or net gain position, respectively. The deferred gain or loss is recognized in earnings in the delivery month applicable to the instrument. Gains and losses related to hedges qualifying for regulatory treatment are refundable or recoverable in gas rates through the Purchased Gas Adjustment (PGA) or in electric rates as a component of the fuel rules mechanism.

b.Notional Amounts.

The gross notional volume of open derivatives is as follows:

	June 30, 2025			December 31, 2024
Commodity derivative contracts		279,520	MWh		307,640	MWh
Commodity derivative contracts		6,662,500	Dth		6,285,000	Dth
FTRs		5,159	MW		2,131	MW

c.Financial Statement Presentation.

MGE purchases and sells exchange-traded and over-the-counter options, swaps, and future contracts. These arrangements are primarily entered into to help stabilize the price risk associated with gas or power purchases. These

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transactions are employed by both MGE's gas and electric segments. Additionally, as a result of the firm transmission agreements that MGE holds on electricity transmission paths in the MISO market, MGE holds financial transmission rights (FTRs). An FTR is a financial instrument that entitles the holder to a stream of revenues or charges based on the differences in hourly day-ahead energy prices between two points on the transmission grid. The fair values of these instruments are offset with a corresponding regulatory asset/liability depending on whether the instruments are in a net loss/gain position. Depending on the nature of the instrument, the gain or loss associated with these transactions will be reflected as cost of gas sold, fuel for electric generation, or purchased power expense in the delivery month applicable to the instrument. As of June 30, 2025, and December 31, 2024, the fair value of exchange traded derivatives and FTRs exceeded their cost basis by $0.7 million and $0.1 million, respectively.

The following table summarizes the fair value of the derivative instruments on the consolidated balance sheets. All derivative instruments in this table are presented on a gross basis and are calculated prior to the netting of instruments with the same counterparty under a master netting agreement as well as the netting of collateral. For financial statement purposes, instruments are netted with the same counterparty under a master netting agreement as well as the netting of collateral.

	Derivative		Derivative
(In thousands)	Assets		Liabilities		Balance Sheet Location
June 30, 2025
Commodity derivative contracts(a)	$	1,455	$	1,192	Other current assets
Commodity derivative contracts(a)		223		47	Other deferred charges
FTRs		258		—	Other current assets
December 31, 2024
Commodity derivative contracts(a)	$	927	$	1,121	Other current liabilities
Commodity derivative contracts(a)		286		140	Other deferred liabilities and other
FTRs		108		—	Other current assets

(a)As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

The following table shows the effect of netting arrangements for recognized derivative assets and liabilities that are subject to a master netting arrangement or similar arrangement on the consolidated balance sheets.

Offsetting of Derivative Assets and Liabilities

(In thousands)	Gross Amounts		Gross Amounts Offset in Balance Sheets			Collateral Posted Against Derivative Positions			Net Amount Presented in Balance Sheets
June 30, 2025
Assets
Commodity derivative contracts	$	1,678	$	(1,239	)	$	—		$	439
FTRs		258		—			—			258
Liabilities
Commodity derivative contracts		1,239		(1,239	)		—			—
December 31, 2024
Assets
Commodity derivative contracts	$	1,213	$	(1,213	)	$	—		$	—
FTRs		108		—			—			108
Liabilities
Commodity derivative contracts		1,261		(1,213	)		(48	)		—

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The following tables summarize the unrealized and realized gains/losses related to the derivative instruments on the consolidated balance sheets and the consolidated statements of income.

	2025						2024
(In thousands)	Current and Long-Term Regulatory Asset (Liability)			Other Current Assets			Current and Long-Term Regulatory Asset (Liability)			Other Current Assets
Three Months Ended June 30:
Balance as of April 1,	$	(1,860	)	$	78		$	3,009		$	275
Unrealized loss		2,118			—			758			—
Realized (loss) gain reclassified to a deferred account		(288	)		288			(537	)		537
Realized (loss) gain reclassified to income statement		(667	)		30			(1,284	)		(285	)
Balance as of June 30,	$	(697	)	$	396		$	1,946		$	527
Six Months Ended June 30:
Balance as of January 1,	$	(60	)	$	388		$	5,226		$	1,569
Unrealized loss		362			—			2,898			—
Realized (loss) gain reclassified to a deferred account		263			(263	)		(2,694	)		2,694
Realized (loss) gain reclassified to income statement		(1,262	)		271			(3,484	)		(3,736	)
Balance as of June 30,	$	(697	)	$	396		$	1,946		$	527

	Realized Losses (Gains)
	2025					2024
(In thousands)	Fuel for Electric Generation/ Purchased Power		Cost of Gas Sold			Fuel for Electric Generation/ Purchased Power		Cost of Gas Sold
Three Months Ended June 30:
Commodity derivative contracts	$	198	$	—		$	1,328	$	—
FTRs		439		—			241		—
Six Months Ended June 30:
Commodity derivative contracts	$	596	$	(203	)	$	3,754	$	3,265
FTRs		598		—			201		—

MGE's commodity derivative contracts and FTRs are subject to regulatory deferral. These derivatives are marked to fair value and are offset with a corresponding regulatory asset or liability. Realized gains and losses are deferred on the consolidated balance sheets and are recognized in earnings in the delivery month applicable to the instrument. As a result of the treatment described above, there are no unrealized gains or losses that flow through earnings.

Certain counterparties extend MGE a credit limit. If MGE exceeds these limits, the counterparties may require collateral to be posted. As of June 30, 2025, and December 31, 2024, no counterparties were in a net liability position.

Nonperformance of counterparties to the non-exchange traded derivatives could expose MGE to credit loss. However, MGE enters into transactions only with companies that meet or exceed strict credit guidelines, and it monitors these counterparties on an ongoing basis to mitigate nonperformance risk in its portfolio. As of June 30, 2025, no counterparties had defaulted.

11.Fair Value of Financial Instruments - MGE Energy and MGE.

Fair value is defined as the price that would be received to sell an asset or would be paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. The accounting standard clarifies that fair value should be based on the assumptions market participants would use when pricing the asset or liability including assumptions about risk. The standard also establishes a

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three-level fair value hierarchy based upon the observability of the assumptions used and requires the use of observable market data when available. The levels are:

Level 1 - Pricing inputs are quoted prices within active markets for identical assets or liabilities.

Level 2 - Pricing inputs are quoted prices within active markets for similar assets or liabilities; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations that are correlated with or otherwise verifiable by observable market data.

Level 3 - Pricing inputs are unobservable and reflect management's best estimate of what market participants would use in pricing the asset or liability.

a.Fair Value of Financial Assets and Liabilities Recorded at the Carrying Amount.

The carrying amount of cash, cash equivalents, and outstanding commercial paper approximates fair market value due to the short maturity of those investments and obligations. The estimated fair market value of long-term debt is based on quoted market prices for similar financial instruments. Since long-term debt is not traded in an active market, it is classified as Level 2. The estimated fair market value of financial instruments are as follows:

	June 30, 2025				December 31, 2024
(In thousands)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt(a)	$	770,775	$	710,479	$	773,400	$	698,765

(a)Includes long-term debt due within one year. Excludes debt issuance costs and unamortized discount of $4.1 million and $4.4 million as of June 30, 2025, and December 31, 2024, respectively.

b.Recurring Fair Value Measurements.

The following table presents the balances of assets and liabilities measured at fair value on a recurring basis for both MGE and MGE Energy.

	Fair Value as of June 30, 2025
(In thousands)	Total		Level 1		Level 2		Level 3
Assets:
Derivatives, net(b)	$	1,936	$	1,416	$	—	$	520
Liabilities:
Derivatives, net(b)	$	1,239	$	916	$	—	$	323
Deferred compensation		6,753		—		6,753		—
Total Liabilities	$	7,992	$	916	$	6,753	$	323

	Fair Value as of December 31, 2024
(In thousands)	Total		Level 1		Level 2		Level 3
Assets:
Derivatives, net(b)	$	1,321	$	987	$	—	$	334
Liabilities:
Derivatives, net(b)	$	1,261	$	480	$	—	$	781
Deferred compensation		6,468		—		6,468		—
Total Liabilities	$	7,729	$	480	$	6,468	$	781

(b)As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

Exchange-traded Investments. Investments include exchange-traded investment securities valued using quoted prices on active exchanges and are therefore classified as Level 1.

Deferred Compensation. The deferred compensation plans allow participants to defer certain cash compensation into notional investment accounts. These amounts are included within "Other deferred liabilities and other" in the consolidated balance sheets. The value of certain deferred compensation obligations is based on the market value of the

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participants' notional investment accounts. The underlying notional investments are comprised primarily of equities, mutual funds, and fixed income securities that are based on directly and indirectly observable market prices. Since the deferred compensation obligations themselves are not exchanged in an active market, they are classified as Level 2.

The value of legacy deferred compensation obligations is based on notional investments that earn interest based upon the semiannual rate of U.S. Treasury Bills having a 26-week maturity increased by 1% compounded monthly with a minimum annual rate of 7%, compounded monthly. The notional investments are based upon observable market data, however, since the deferred compensation obligations themselves are not exchanged in an active market, they are classified as Level 2.

Derivatives. Derivatives include exchange-traded derivative contracts, over-the-counter transactions, and FTRs. Most exchange-traded derivative contracts are valued based on unadjusted quoted prices in active markets and are therefore classified as Level 1. A small number of exchange-traded derivative contracts are valued using quoted market pricing in markets with insufficient volumes and are therefore considered unobservable and classified as Level 3. Transactions done with an over-the-counter party are on inactive markets and are therefore classified as Level 3. These transactions are valued based on quoted prices from markets with similar exchange-traded transactions. FTRs are priced based upon monthly auction results for identical or similar instruments in a closed market with limited data available and are therefore classified as Level 3.

The following table summarizes the changes in Level 3 commodity derivative assets and liabilities measured at fair value on a recurring basis.

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In thousands)	2025		2024		2025		2024
Beginning balance	$	515	$	(1,726)	$	(447)	$	(2,604)
Realized and unrealized gains (losses):
Included in regulatory assets		—		294		—		1,172
Included in regulatory liability		(318)		—		642		—
Included in earnings		(665)		(1,330)		(1,262)		(3,855)
Settlements		665		1,330		1,264		3,855
Balance as of June 30,	$	197	$	(1,432)	$	197	$	(1,432)

The following table presents total realized and unrealized gains (losses) included in income for Level 3 assets and liabilities measured at fair value on a recurring basis(c).

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In thousands)	2025		2024		2025		2024
Purchased power expense	$	(665)	$	(1,330)	$	(1,262)	$	(3,855)

(c)MGE's exchange-traded derivative contracts, over-the-counter party transactions, purchased power agreement, and FTRs are subject to regulatory deferral. These derivatives are therefore marked to fair value and are offset in the financial statements with a corresponding regulatory asset or liability.

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12.Joint Plant Construction Project Ownership - MGE Energy and MGE

MGE has ownership interests in generation projects with other co-owners, some of which are under construction, as shown in the following table. Incurred costs are reflected in "Property, plant, and equipment, net" or "Construction work in progress" on the consolidated balance sheets.

Project	Ownership Interest	Source	Share of Generation	Share of Estimated Costs(a)	Costs incurred as of June 30, 2025(a)	Date of Commercial Operation
Paris(b)	10%	Battery	11 MW	$25 million(g)	$23.4 million	June 2025 Battery
Darien(c)	10%	Solar/Battery	25 MW/7.5 MW	$63 million(g)	$46.3 million	March 2025 Solar 2026 Battery(h)
Koshkonong(d)	10%	Solar/Battery	30 MW/16.5 MW	$104 million(g)	$24.8 million	2026 Solar(h) 2027 Battery(h)
High Noon(e)	10%	Solar/Battery	30 MW/16.5 MW	$99 million	$17.8 million	2027(h)
Columbia Energy Dome(f)	19%	Storage	3 MW	$17 million	$0.7 million	2027(h)

(a)Excluding AFUDC.

(b)Paris Solar-Battery Park is located in the Town of Paris in Kenosha County, Wisconsin.

(c)Darien Solar Energy Center is located in Walworth and Rock Counties in southern Wisconsin.

(d)Koshkonong Solar Energy Center is located in the Towns of Christiana and Deerfield in Dane County, Wisconsin.

(e)High Noon Solar Project is located in Columbia County, Wisconsin.

(f)Columbia Energy Dome is located in Columbia County, Wisconsin.

(g)Estimated costs are expected to exceed PSCW previously approved Certificate of Authority (CA) levels. Notifications are provided to the PSCW when costs increase above CA levels. MGE has and will continue to request recovery of the updates in its rate case proceedings.

(h)Estimated date of commercial operation.

MGE received specific approval to recover 100% AFUDC on Paris, Darien, Koshkonong, High Noon, and Columbia Energy Dome. During the three and six months ended June 30, 2025, MGE recognized $0.5 million and $2.1 million, respectively, after tax, in AFUDC for these projects compared to $1.5 million and $2.7 million, respectively, after tax, for the comparable periods in 2024.

13.Revenue - MGE Energy and MGE.

Revenues disaggregated by revenue source were as follows:

	Three Months Ended				Six Months Ended
(In thousands)	June 30,				June 30,
Electric revenues	2025		2024		2025		2024
Residential	$	43,182	$	40,321	$	88,321	$	81,462
Commercial		64,027		64,161		124,662		124,024
Industrial		3,117		3,445		6,081		6,855
Other-retail/municipal		10,342		10,403		19,690		20,093
Total retail		120,668		118,330		238,754		232,434
Sales to the market		7,840		1,519		14,320		2,595
Other		805		534		1,693		1,479
Total electric revenues		129,313		120,383		254,767		236,508
Gas revenues
Residential		17,956		15,589		71,824		58,987
Commercial/Industrial		10,434		7,876		47,547		37,400
Total retail		28,390		23,465		119,371		96,387
Gas transportation		1,384		1,505		3,697		3,585
Other		151		146		338		313
Total gas revenues		29,925		25,116		123,406		100,285
Non-regulated energy revenues		214		214		249		256
Total Operating Revenue	$	159,452	$	145,713	$	378,422	$	337,049

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14.Segment Information - MGE Energy and MGE

MGE Energy operates in the following business segments: electric utility, gas utility, nonregulated energy, transmission investment, and all other. See Footnote 22 to the consolidated financial statements included in Part II, Item 8 of the 2024 Annual Report on Form 10-K for additional discussion of each of these segments.

Fuel and purchased power and Purchased gas costs are significant segment expenses as defined in Segment Reporting. The Chief Operating Decision Maker does not review disaggregated assets on a segment basis; therefore, such information is not presented.

The following table shows segment information for MGE Energy's and MGE's operations:

(In thousands) MGE Energy	Electric			Gas			Non-Regulated Energy			Transmission Investment			Total Reportable Segments			All Others			Consolidation/ Elimination			Consolidated Total
Three Months Ended June 30, 2025
Operating revenues	$	129,313		$	29,925		$	214		$	—		$	159,452		$	—		$	—		$	159,452
Interdepartmental revenues		(28	)		2,558			11,121			—			13,651			—			(13,651	)		—
Total operating revenues		129,285			32,483			11,335			—			173,103			—			(13,651	)		159,452
Fuel and purchased power		(22,524	)		—			—			—			(22,524	)		—			670			(21,854	)
Purchased gas costs		—			(13,211	)		—			—			(13,211	)		—			1,898			(11,313	)
Depreciation and amortization		(22,094	)		(4,347	)		(1,913	)		—			(28,354	)		—			—			(28,354	)
Interest expense		(6,485	)		(1,768	)		(889	)		—			(9,142	)		—			—			(9,142	)
Other segment items(a)		(58,130	)		(15,015	)		(23	)		—			(73,168	)		(291	)		11,083			(62,376	)
Income tax (provision) benefit		(472	)		561			(2,318	)		(835	)		(3,064	)		89			—			(2,975	)
Equity in earnings of investments		—			—			—			3,060			3,060			—			—			3,060
Net income (loss)		19,580			(1,297	)		6,192			2,225			26,700			(202	)		—			26,498
Three Months Ended June 30, 2024
Operating revenues	$	120,383		$	25,116		$	214		$	—		$	145,713		$	—		$	—		$	145,713
Interdepartmental revenues		(55	)		2,172			10,946			—			13,063			—			(13,063	)		—
Total operating revenues		120,328			27,288			11,160			—			158,776			—			(13,063	)		145,713
Fuel and purchased power		(20,840	)		—			—			—			(20,840	)		—			753			(20,087	)
Purchased gas costs		—			(7,720	)		—			—			(7,720	)		—			1,427			(6,293	)
Depreciation and amortization		(20,888	)		(4,163	)		(1,881	)		—			(26,932	)		—			—			(26,932	)
Interest expense		(6,323	)		(1,709	)		(957	)		—			(8,989	)		—			—			(8,989	)
Other segment items(a)		(57,257	)		(14,456	)		(17	)		—			(71,730	)		(79	)		10,883			(60,926	)
Income tax (provision) benefit		641			810			(2,262	)		(758	)		(1,569	)		97			—			(1,472	)
Equity in earnings of investments		—			—			—			2,780			2,780			—			—			2,780
Net income		15,661			50			6,043			2,022			23,776			18			—			23,794
Six Months Ended June 30, 2025
Operating revenues	$	254,767		$	123,406		$	249		$	—		$	378,422		$	—		$	—		$	378,422
Interdepartmental revenues		(76	)		9,030			22,225			—			31,179			—			(31,179	)		—
Total operating revenues		254,691			132,436			22,474			—			409,601			—			(31,179	)		378,422
Fuel and purchased power		(45,630	)		—			—			—			(45,630	)		—			1,829			(43,801	)
Purchased gas costs		—			(72,501	)		—			—			(72,501	)		—			7,224			(65,277	)
Depreciation and amortization		(43,629	)		(8,579	)		(3,824	)		—			(56,032	)		—			—			(56,032	)
Interest expense		(12,978	)		(3,531	)		(1,795	)		—			(18,304	)		—			—			(18,304	)
Other segment items(a)		(114,109	)		(31,111	)		(67	)		—			(145,287	)		(727	)		22,126			(123,888	)
Income tax (provision) benefit		1,430			(4,426	)		(4,573	)		(1,702	)		(9,271	)		—			—			(9,271	)
Equity in earnings of investments		—			—			—			6,241			6,241			—			—			6,241
Net income (loss)		39,775			12,288			12,215			4,539			68,817			(727	)		—			68,090
Six Months Ended June 30, 2024
Operating revenues	$	236,508		$	100,285		$	256		$	—		$	337,049		$	—		$	—		$	337,049
Interdepartmental revenues		(109	)		7,383			21,773			—			29,047			—			(29,047	)		—
Total operating revenues		236,399			107,668			22,029			—			366,096			—			(29,047	)		337,049
Fuel and purchased power		(43,910	)		—			—			—			(43,910	)		—			1,677			(42,233	)
Purchased gas costs		—			(53,893	)		—			—			(53,893	)		—			5,723			(48,170	)
Depreciation and amortization		(41,538	)		(8,245	)		(3,749	)		—			(53,532	)		—			—			(53,532	)
Interest expense		(12,651	)		(3,419	)		(1,931	)		—			(18,001	)		—			—			(18,001	)
Other segment items(a)		(110,802	)		(29,161	)		(41	)		(2	)		(140,006	)		(392	)		21,647			(118,751	)
Income tax (provision) benefit		3,926			(2,286	)		(4,442	)		(1,506	)		(4,308	)		28			—			(4,280	)
Equity in earnings of investments		—			—			—			5,526			5,526			—			—			5,526
Net income (loss)		31,424			10,664			11,866			4,018			57,972			(364	)		—			57,608

(a)Other segment items include AFUDC Income, Other Income, Net, Other Operations and Maintenance, Other General Taxes, and Interest Revenue.

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(In thousands) MGE	Electric			Gas			Non-Regulated Energy			Total Reportable Segments			Consolidation/ Elimination			Consolidated Total
Three Months Ended June 30, 2025
Operating revenues	$	129,313		$	29,925		$	214		$	159,452		$	—		$	159,452
Interdepartmental revenues		(28	)		2,558			11,121			13,651			(13,651	)		—
Total operating revenues		129,285			32,483			11,335			173,103			(13,651	)		159,452
Fuel and purchased power		(22,524	)		—			—			(22,524	)		670			(21,854	)
Purchased gas costs		—			(13,211	)		—			(13,211	)		1,898			(11,313	)
Depreciation and amortization		(22,094	)		(4,347	)		(1,913	)		(28,354	)		—			(28,354	)
Interest expense		(6,485	)		(1,768	)		(889	)		(9,142	)		—			(9,142	)
Other segment items(a)		(58,130	)		(15,015	)		(23	)		(73,168	)		11,083			(62,085	)
Income tax benefit (provision)		(472	)		561			(2,318	)		(2,229	)		—			(2,229	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(5,714	)		(5,714	)
Net income attributable to MGE		19,580			(1,297	)		6,192			24,475			(5,714	)		18,761
Three Months Ended June 30, 2024
Operating revenues	$	120,383		$	25,116		$	214		$	145,713		$	—		$	145,713
Interdepartmental revenues		(55	)		2,172			10,946			13,063			(13,063	)		—
Total operating revenues		120,328			27,288			11,160			158,776			(13,063	)		145,713
Fuel and purchased power		(20,840	)		—			—			(20,840	)		753			(20,087	)
Purchased gas costs		—			(7,720	)		—			(7,720	)		1,427			(6,293	)
Depreciation and amortization		(20,888	)		(4,163	)		(1,881	)		(26,932	)		—			(26,932	)
Interest expense		(6,323	)		(1,709	)		(957	)		(8,989	)		—			(8,989	)
Other segment items(a)		(57,257	)		(14,456	)		(17	)		(71,730	)		10,883			(60,847	)
Income tax benefit (provision)		641			810			(2,262	)		(811	)		—			(811	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(5,766	)		(5,766	)
Net income attributable to MGE		15,661			50			6,043			21,754			(5,766	)		15,988
Six Months Ended June 30, 2025
Operating revenues	$	254,767		$	123,406		$	249		$	378,422		$	—		$	378,422
Interdepartmental revenues		(76	)		9,030			22,225			31,179			(31,179	)		—
Total operating revenues		254,691			132,436			22,474			409,601			(31,179	)		378,422
Fuel and purchased power		(45,630	)		—			—			(45,630	)		1,829			(43,801	)
Purchased gas costs		—			(72,501	)		—			(72,501	)		7,224			(65,277	)
Depreciation and amortization		(43,629	)		(8,579	)		(3,824	)		(56,032	)		—			(56,032	)
Interest expense		(12,978	)		(3,531	)		(1,795	)		(18,304	)		—			(18,304	)
Other segment items(a)		(114,109	)		(31,111	)		(67	)		(145,287	)		22,126			(123,161	)
Income tax benefit (provision)		1,430			(4,426	)		(4,573	)		(7,569	)		—			(7,569	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(11,313	)		(11,313	)
Net income attributable to MGE		39,775			12,288			12,215			64,278			(11,313	)		52,965
Six Months Ended June 30, 2024
Operating revenues	$	236,508		$	100,285		$	256		$	337,049		$	—		$	337,049
Interdepartmental revenues		(109	)		7,383			21,773			29,047			(29,047	)		—
Total operating revenues		236,399			107,668			22,029			366,096			(29,047	)		337,049
Fuel and purchased power		(43,910	)		—			—			(43,910	)		1,677			(42,233	)
Purchased gas costs		—			(53,893	)		—			(53,893	)		5,723			(48,170	)
Depreciation and amortization		(41,538	)		(8,245	)		(3,749	)		(53,532	)		—			(53,532	)
Interest expense		(12,651	)		(3,419	)		(1,931	)		(18,001	)		—			(18,001	)
Other segment items(a)		(110,802	)		(29,161	)		(41	)		(140,004	)		21,647			(118,357	)
Income tax benefit (provision)		3,926			(2,286	)		(4,442	)		(2,802	)		—			(2,802	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(11,363	)		(11,363	)
Net income attributable to MGE		31,424			10,664			11,866			53,954			(11,363	)		42,591

(a)Other segment items include AFUDC Income, Other Income, Net, Other Operations and Maintenance, Other General Taxes, and Interest Revenue.

The following table shows segment information for MGE Energy's and MGE's capital expenditures:

	Utility				Consolidated
(In thousands) MGE Energy	Electric		Gas		Non-regulated Energy		Transmission Investment		All Others		Consolidation/ Elimination Entries		Total
Six Months Ended June 30, 2025	$	83,034	$	22,975	$	5,744	$	—	$	—	$	—	$	111,753
Six Months Ended June 30, 2024		86,755		20,879		3,988		—		—		—		111,622

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	Utility				Consolidated
(In thousands) MGE	Electric		Gas		Non-regulated Energy		Consolidation/ Elimination Entries		Total
Six Months Ended June 30, 2025	$	83,034	$	22,975	$	5,744	$	—	$	111,753
Six Months Ended June 30, 2024		86,755		20,879		3,988		—		111,622

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Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations.

General

MGE Energy is an investor-owned public utility holding company operating through subsidiaries in five business segments:

•Regulated electric utility operations, conducted through MGE, which generate and distribute electricity to approximately 167,000 customers in Dane County, Wisconsin,

•Regulated gas utility operations, conducted through MGE, which distribute natural gas to approximately 178,000 customers in seven south-central and western Wisconsin counties,

•Nonregulated energy operations, conducted through MGE Power and its subsidiaries, which owns interests in electric generating capacity that is leased to MGE,

•Transmission investments, representing our equity investment in ATC, which owns and operates electric transmission facilities primarily in Wisconsin, and ATC Holdco, a company created to facilitate out-of-state electric transmission development and investments, and

•All other, which includes investing in companies and property that relate to the regulated operations and financing of the regulated operations, through its wholly owned subsidiaries CWDC, MAGAEL, and North Mendota, and corporate operations and services.

MGE plans to continue to focus on growing earnings while controlling operating and fuel costs. MGE's goal is to provide safe and efficient operations in addition to providing customer value. We believe it is critical to maintain a strong credit rating consistent with financial strength in MGE in order to accomplish these goals.

The ownership/leasing structure for our nonregulated energy operations was adopted under applicable state regulatory guidelines for MGE's participation in these generation facilities, consisting principally of a stable return on the equity investment in the new generation facilities over the term of the related leases. The nonregulated energy operations include an ownership interest in two coal-fired generating units in Oak Creek, Wisconsin and a partial ownership of a cogeneration project on the University of Wisconsin-Madison campus. A third party operates the units in Oak Creek, and MGE operates the cogeneration project. Due to the nature of MGE's participation in these facilities, the results of MGE Energy's nonregulated operations are also consolidated into MGE's consolidated financial position and results of operations under applicable accounting standards.

Executive Overview

We principally earn revenue and generate cash from operations by providing electric and natural gas utility services, including electric power generation and electric power and gas distribution. The earnings and cash flows from the utility business are sensitive to various external factors, including, but not limited to:

•Weather, and its impact on customer sales,

•Economic conditions, including current business activity and employment and their impact on customer demand,

•Regulation and regulatory issues, and their impact on the timing and recovery of costs,

•Energy commodity prices, including natural gas prices,

•Equity price risk pertaining to pension-related assets,

•Credit market conditions, including interest rates and our debt credit rating,

•Environmental laws and regulations, including adopted and pending environmental rule changes, and

•Other factors listed in Item 1A. Risk Factors in our 2024 Annual Report on Form 10-K.

During the three months ended June 30, 2025, MGE Energy's earnings were $26.5 million, or $0.73 per share, compared to $23.8 million, or $0.66 per share, during the same period in the prior year. MGE's earnings during the three months ended June 30, 2025, were $18.8 million compared to $16.0 million during the same period in the prior year.

During the six months ended June 30, 2025, MGE Energy's earnings were $68.1 million, or $1.86 per share, compared to $57.6 million, or $1.59 per share, during the same period in the prior year. MGE's earnings during the six months ended June 30, 2025, were $53.0 million compared to $42.6 million during the same period in the prior year.

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MGE Energy's net income was derived from our business segments as follows:

	Three Months Ended				Six Months Ended
(In millions)	June 30,				June 30,
Business Segment:	2025		2024		2025		2024
Electric Utility	$	19.6	$	15.6	$	39.8	$	31.4
Gas Utility		(1.3)		0.1		12.3		10.7
Nonregulated Energy		6.2		6.1		12.2		11.9
Transmission Investments		2.2		2.0		4.5		4.0
All Other		(0.2)		—		(0.7)		(0.4)
Net Income	$	26.5	$	23.8	$	68.1	$	57.6

Our net income during the three and six months ended June 30, 2025, compared to the same periods in the prior year, primarily reflects the effects of the following factors:

Electric Utility

An increase in electric investments, as part of the 2025 rate case, contributed to an increase in earnings for the three and six months ended June 30, 2025, as compared to the same periods in the prior year. Favorable weather contributed to higher electric residential sales for the three and six months ended June 30, 2025, compared to the same periods in the prior year.

Gas Utility

Higher gas retail sales in the first half of 2025 contributed to higher gas earnings for the six months ended June 30, 2025, compared to the same period in the prior year. Gas retail sales increased approximately 16%. Heating degree days (a measure for determining the impact of weather during the heating season) increased by approximately 18% in the first six months of 2025 compared to the same period in the prior year.

Significant Events

The following events affected the first six months of 2025:

2025 Rate Proceeding: In December 2023, the PSCW approved a 4.17% increase to electric rates and 1.32% increase to gas rates for 2025. The PSCW approved a 2025 Fuel Cost Plan in December 2024. The plan lowered the 2025 increase in electric rates to 2.63%, reflecting lower expected fuel costs. See "Other Matters" below for additional information on the 2025 rate proceeding.

The 2025 rate order includes an earnings sharing mechanism, under which, if MGE earns above the 9.7% ROE authorized in the rate order: (i) the utility will retain 100% of earnings for the first 15 basis points above the authorized ROE; (ii) 50% of the next 60 basis points will be required to be deferred and returned to customers; and (iii) 100% of any remaining excess earnings will be required to be refunded to customers. The earnings calculation excludes fuel rules adjustments.

2025 Deferred Fuel Savings: MGE had deferred fuel savings through the six months ended June 30, 2025. As of June 30, 2025, MGE deferred $2.5 million of 2025 fuel savings. These costs will be subject to the PSCW's annual review of 2025 fuel costs, expected to be completed during 2026. See Footnote 9 of the Notes to the Consolidated Financial Statements in this Report for further information regarding fuel cost proceedings.

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Large Scale Utility Projects: Large scale generation projects recently completed or under construction, are shown in the following table. Incurred costs are reflected in "Property, plant, and equipment, net" for projects placed in service, or "Construction work in progress" for projects under construction on the consolidated balance sheets.

Project	Ownership Interest	Source	Share of Generation	Share of Estimated Costs(a)	Costs incurred as of June 30, 2025(a)	Date of Commercial Operation
Paris	10%	Battery	11 MW	$25 million(d)	$23.4 million(b)	June 2025 Battery(f)
Darien	10%	Solar/Battery	25 MW/7.5 MW	$63 million(d)	$46.3 million(b)	March 2025 Solar 2026(c) Battery
Koshkonong	10%	Solar/Battery	30 MW/16.5 MW	$104 million(d)	$24.8 million(b)	2026(c) Solar 2027(c) Battery
High Noon	10%	Solar/Battery	30 MW/16.5 MW	$99 million	$17.8 million	2027(c)
Sunnyside	100%	Solar/Battery	20MW/40MW	$112 million	$1.0 million	2026(c) Solar 2027(c) Battery
Columbia Energy Dome	19%	Storage	3 MW	$17 million	$0.7 million	2027(c)
Ursa(e)	10%	Solar	20 MW	$46 million	$0.3 million	2027(c)
Badger Hollow(e)	10%	Wind	11.2 MW	$36 million	$0.3 million	2027(c)
Whitetail(e)	10%	Wind	6.7 MW	$23 million	$0.1 million	2027(c)
Forward Repower(e)	13%	Wind	18 MW	$14 million	$0.3 million	2027(c)
Dawn Harvest(e)	10%	Solar	15 MW	$34 million	$0.6 million	2028(c)
Good Oak(e)	10%	Solar	9.8 MW	$22 million	$1.4 million	2028(c)
Gristmill(e)	10%	Solar	6.7 MW	$15 million	$1.3 million	2028(c)
Saratoga(e)	10%	Solar/Battery	15 MW/5 MW	$46 million	$1.1 million	2028(c)

(a)Excluding AFUDC.

(b)MGE received specific approval to recover 100% AFUDC. After tax, MGE recognized $5.3 million, $3.1 million, $0.8 million, and $0.1 million of AFUDC equity through June 30, 2025, on Paris, Darien, Koshkonong, and High Noon, respectively, during construction. AFUDC has been excluded from the costs incurred in the table above.

(c)Estimated date of commercial operation.

(d)Estimated costs are expected to exceed PSCW previously approved CA levels. Notifications are provided to the PSCW when costs increase above CA levels. MGE has and will continue to request recovery of the updates in its rate case proceedings.

(e)Pending approval by the PSCW.

(f)The Paris Battery project is located within the Paris Solar-Battery Park, which also includes the Paris Solar project, which was placed in service in December 2024.

In the near term, several items may affect us, including:

2024 Annual Fuel Proceeding: MGE had fuel savings in 2024. As of December 31, 2024, MGE deferred $3.0 million of 2024 fuel savings. The PSCW has completed the annual review of 2024 fuel costs and gave approval for MGE to return these savings in October 2025. There was no change to the costs to be refunded in the fuel rule proceedings from the amount MGE deferred in the previous year.

Environmental Initiatives: There are proposed legislative rules and initiatives involving matters related to air emissions, water effluent, hazardous materials, and greenhouse gases, all of which affect generation plant capital expenditures and operating costs as well as future operational planning. Legislation and rulemaking addressing climate change and related matters could significantly affect the costs of owning and operating fossil-fueled generating plants. MGE would expect to seek and receive recovery of any such costs in rates. However, it is difficult to estimate the amount of such costs due to the uncertainty as to the timing and form of any legislation or rules, the timing and effects of any judicial review, and the scope and time of the recovery of costs in rates, which may occur after those costs have been incurred and paid.

Future Generation – 80% carbon reduction target by 2030 (from 2005 levels): MGE has outlined initiatives to achieve our target.

•Transitioning away from coal. Columbia: MGE, along with the other plant co-owners, announced plans to retire Columbia Unit 1 and Unit 2 by the end of 2029. Final timing and retirement dates for Units 1 and 2 are subject to change depending on operational and regulatory considerations, capacity needs, and other factors impacting one or more of the Columbia co-owners. MGE has a plan, which it continues to evaluate, to replace the generation from Columbia while maintaining electric service reliability. In December 2024, MGE and Columbia's co-owners announced plans to explore converting at least one unit of Columbia to natural gas before the end of 2029.

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Elm Road Units: MGE, along with the plant co-owners, announced plans to end the use of coal as a primary fuel at the Elm Road Units and transition the plant to natural gas. Transition plans and costs will be subject to PSCW approval. MGE's remaining use of coal is expected to be further reduced as the Elm Road Units transition to natural gas. By the end of 2030, coal is expected to be used only as a backup fuel at the Elm Road Units. This transition will help MGE meet its 2030 carbon reduction goals. By the end of 2032, MGE expects that the Elm Road Units will be fully transitioned away from coal, which will eliminate coal as an internal generation source for MGE.

•Growing renewable generation and storage. MGE is seeking to acquire, or has acquired, joint interests in several renewable generation and storage projects. The forecasted capital expenditures include approximately 178 MW of solar, 18 MW of wind, and 118 MW of battery storage, which include projects approved or pending PSCW approval. See the 2025-2029 capital expenditures forecast disclosed in Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations in our 2024 Annual Report on Form 10-K.

Environmental Initiatives – Natural gas distribution: Building upon our long-standing commitment to providing affordable, sustainable energy, MGE has set a goal to achieve net-zero methane emissions from its natural gas distribution system by 2035. If MGE can accelerate plans to achieve net-zero methane emissions from its natural gas system—through the evolution of new technologies, such as renewable natural gas—it will. MGE is working to reduce overall emissions from its natural gas distribution system in a quick and cost-effective manner. For customers who want to reduce their environmental footprint further, MGE introduced a renewable natural gas program in May 2024, after approval by the PSCW. MGE purchases renewable thermal credits on behalf of customers who voluntarily elect in the program to offset the emissions associated with the customer's monthly natural gas usage.

Solar Procurement Disruptions: MGE is monitoring import regulations under the Uyghur Forced Labor Protection Act and the U.S. Department of Commerce's new solar tariffs. These disruptions have a potential to impact current and future solar projects which may result in an increase in costs or delays in construction timelines. In the event that such disruptions cause costs to exceed the levels approved for specific projects, we have filed, and expect to continue to file, notifications with the PSCW and expect to request recovery of any increases in MGE's future rate proceedings. See "Other Matters" below for additional information on the solar procurement disruptions.

Tariffs: MGE is monitoring the actions of the Trump Administration with respect to certain proposed or recently implemented import tariffs on foreign goods. These tariffs have a potential impact on cost of operations and on current and future capital projects. See "Other Matters" below for additional information on tariffs.

Tax Update: On July 4, 2025, the One Big Beautiful Bill Act (OBBBA) was signed into law, introducing significant changes to tax credits and compliance requirements. See "Other Matters" below for additional information on the OBBBA.

Financing and Equity Issuance Plans: MGE Energy annually evaluates its financing plan, dividend practices, and credit line sizing, focusing on its credit rating while meeting cash needs to fund capital requirements, including construction expenditures, retire debt, pay dividends, and operating expenses. As of June 30, 2025, MGE had $280 million of remaining regulatory authority from the PSCW to issue long-term debt to finance authorized utility capital expenditures. During the beginning of 2025, MGE Energy issued new shares of common stock to participants in its Direct Stock Purchase and Dividend Reinvestment Plan. As of May 2025, MGE Energy began purchasing shares in the open market for participants in the Direct Stock Purchase and Dividend Reinvestment Plan.

The following discussion is based on the business segments as discussed in Footnote 14 of the Notes to Consolidated Financial Statements in this Report.

Results of Operations

Three Months Ended June 30, 2025 and 2024

Electric sales and revenues

The following table compares MGE's electric revenues and electric kWh sales by customer class for each of the periods indicated:

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	Revenues					Sales (kWh)
	Three Months Ended June 30,					Three Months Ended June 30,
(In thousands, except CDD)	2025		2024		% Change	2025	2024	% Change
Residential	$	43,182	$	40,321	7.1%	203,344	193,886	4.9%
Commercial		64,027		64,161	(0.2)%	439,972	440,151	—%
Industrial		3,117		3,445	(9.5)%	35,737	36,822	(2.9)%
Other-retail/municipal		10,342		10,403	(0.6)%	99,198	97,648	1.6%
Total retail		120,668		118,330	2.0%	778,251	768,507	1.3%
Sales to the market		7,840		1,519	n.m.%	92,400	36,706	n.m.%
Other		805		534	50.7%	—	—	—%
Total	$	129,313	$	120,383	7.4%	870,651	805,213	8.1%
Cooling degree days (normal 208)						223	207	7.7%

n.m. not meaningful

Electric revenue increased $8.9 million during the three months ended June 30, 2025, compared to the same period in the prior year, due to the following:

(In millions)
Sales to the market	$	6.3
Rate changes		2.4
Increase in residential volume		1.6
Customer fixed and demand charges		1.4
Other		0.3
Revenue subject to refund, net		(3.1)
Total	$	8.9

•Sales to the market. Sales to the market typically occur when MGE has more generation in the MISO market than are needed for its customer demand. The excess electricity is then sold to other utilities or power marketers in the MISO market. During the three months ended June 30, 2025, market volumes increased compared to the same period in the prior year, reflecting an increase in sales. Additionally, the cost of capacity sold increased, contributing to the revenue generated from increased sales to the market from excess generation and purchases. The revenue generated from these sales is largely offset by fuel rules costs, and do not have a significant impact on net income. See fuel rules discussion in Footnote 9 of the Notes to Consolidated Financial Statements in this Report.

•Rate changes. In December 2023, the PSCW authorized MGE to increase 2025 rates for retail electric customers by approximately 2.63%. Rates charged to retail customers during the three months ended June 30, 2025, were $2.4 million higher than those charged during the same period in the prior year. See Footnote 9 of the Notes to Consolidated Financial Statements in this Report for further information on the rate increase. Any increase in rates associated with fuel or purchase power costs are generally offset by fuel and purchased power costs and do not have a significant impact on net income.

•Volume. During the three months ended June 30, 2025, residential sales increased by approximately 5% compared to the same period in the prior year. This increase was driven by differences in the weather experienced during the three months ended June 30, 2025, compared to the same period in the prior year. Temperatures, on average, were warmer than normal in the second quarter of 2025.

•Customer fixed and demand charges. During the three months ended June 30, 2025, fixed and demand charges increased $1.4 million, primarily attributable to the increase in demand charges for commercial customers.

•Revenue subject to refund. For cost recovery mechanisms, any over-collection of revenues resulting from costs authorized to be collected from customers in rates exceeding actual costs is recorded as a reduction of revenue in the period incurred, as the over-collection is expected to be refunded to customers in a subsequent period. In the year the over-collection is refunded, rates are reduced and offset as revenue subject to refund. There is no net income impact in the year the costs are refunded.

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Electric fuel and purchased power

	Three Months Ended June 30,
(In millions)	2025		2024		$ Change
Fuel for electric generation	$	16.3	$	11.2	$	5.1
Purchased power		5.6		8.9		(3.3)

The $5.1 million increase in fuel for electric generation was due to an approximately 22% increase in internal generation driven by an increase in sales and 19% increase in the average cost, each compared to the same period in the prior year.

Excluding deferred fuel costs, purchased power decreased $1.2 million. The decrease in purchased power was due to an approximately 48% decrease in market purchases as a result of increased internal generation. This decrease was partially offset by an approximately 59% increase in average cost. Deferred fuel cost recovered during the three months ended June 30, 2024, was $2.1 million. There were no deferred fuel costs recovered during the three months ended June 30, 2025.

Fuel and purchased power costs are generally offset by electric revenue and do not have a significant impact on net income. MGE expects to seek and receive recovery of fuel and purchased power costs that exceed the fuel rules bandwidth in customer rates. See Footnote 9 of the Notes to Consolidated Financial Statements in this Report for further information on the fuel rules bandwidth.

Gas deliveries and revenues

The following table compares MGE's gas revenues and gas therms delivered by customer class for each of the periods indicated:

	Revenues					Therms Delivered
(In thousands, except HDD and average	Three Months Ended June 30,					Three Months Ended June 30,
rate per therm of retail customer)	2025		2024		% Change	2025	2024	% Change
Residential	$	17,956	$	15,589	15.2%	13,034	11,822	10.3%
Commercial/Industrial		10,434		7,876	32.5%	14,484	13,824	4.8%
Total retail		28,390		23,465	21.0%	27,518	25,646	7.3%
Gas transportation		1,384		1,505	(8.0)%	15,429	15,367	0.4%
Other		151		146	3.4%	—	—	—%
Total	$	29,925	$	25,116	19.1%	42,947	41,013	4.7%
Heating degree days (normal 782)						843	599	40.7%
Average rate per therm of retail customer	$	1.032	$	0.915	12.8%

Gas revenue increased $4.8 million during the three months ended June 30, 2025, compared to the same period in the prior year, due to the following:

(In millions)
Rate changes	$	5.6
Increase in volume		0.4
Other		(0.9)
Revenue subject to refund, net		(0.3)
Total	$	4.8

•Rate changes. In December 2023, the PSCW authorized MGE to increase 2025 rates for retail gas customers by approximately 1.32%.

MGE recovers the cost of natural gas in its gas segment through the purchased gas adjustment clause (PGA). Under the PGA, MGE is able to pass through to its gas customers the cost of gas. Changes in PGA recoveries affect revenues but do not change net income in view of the pass-through treatment of the costs. Payments for natural gas increased, driving higher rates during the three months ended June 30, 2025.

The average retail rate per therm excluding customer fixed charges for the three months ended June 30, 2025, increased approximately 13% compared to the same period in the prior year, reflecting an increase in natural gas commodity costs (recovered through the PGA).

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Cost of gas sold

Cost of gas sold increased $5.0 million during the three months ended June 30, 2025, compared to the same period in the prior year. Cost per therm increased approximately 67% and therms delivered increased approximately 8%. MGE recovers the cost of natural gas in its gas segment through the PGA as described under gas deliveries and revenues above.

Consolidated operations and maintenance expenses

During the three months ended June 30, 2025, operations and maintenance expenses increased $1.1 million, compared to the same period in the prior year. The following contributed to the net change:

(In millions)
Increased other expenses	$	0.7
Increased transmission costs		0.6
Increased gas distribution expenses		0.4
Increased electric production expenses		0.4
Decreased electric distribution expenses		(0.6)
Decreased administrative and general costs		(0.4)
Total	$	1.1

Consolidated depreciation expense

Electric depreciation expense increased $1.2 million and gas depreciation expense increased $0.2 million during the three months ended June 30, 2025, compared to the same period in the prior year. Paris solar was placed in service in December 2024 and Darien solar was placed in service in March 2025. The timing of the in-service dates contributed to the increase in electric depreciation expense.

Electric and gas other income

Electric other income increased $0.8 million and gas other income decreased $1.2 million during the three months ended June 30, 2025, compared to the same period in the prior year, primarily related to pension and other postretirement, excluding service costs. The PSCW has approved MGE to defer as a regulatory asset or liability, the difference between actual pension and other postretirement costs included in rates and to be recovered or refunded in a future rate proceeding. Pension and other postretirement cost is generally offset by electric and gas revenue and does not have a significant impact on net income.

Nonregulated Energy Operations - MGE Energy and MGE

The nonregulated energy operations are conducted through MGE Energy's subsidiaries: MGE Power Elm Road (the Elm Road Units) and MGE Power West Campus (WCCF), which have been formed to own and lease electric generating capacity to assist MGE. During the three months ended June 30, 2025 and 2024, net income at the nonregulated energy operations segment was $6.2 million and $6.0 million, respectively.

Transmission Investment Operations - MGE Energy

The transmission investment segment holds our interest in ATC and ATC Holdco, and its income reflects our equity in the earnings of those investments. ATC Holdco was formed in December 2016 to pursue transmission development opportunities that typically have long development and investment lead times before becoming operational. During the three months ended June 30, 2025 and 2024, other income at the transmission investment segment primarily reflects ATC's operations and was $3.1 million and $2.8 million, respectively. See Footnote 3 of the Notes to Consolidated Financial Statements in this Report for summarized financial information regarding ATC.

Consolidated Income Taxes - MGE Energy and MGE

See Footnote 4 of the Notes to Consolidated Financial Statements in this Report for the effective tax rate reconciliation.

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Noncontrolling Interest, Net of Tax - MGE

Noncontrolling interest, net of tax, reflects the accounting required for MGE Energy's interest in MGE Power Elm Road (the Elm Road Units) and MGE Power West Campus (WCCF). MGE Energy owns 100% of MGE Power Elm Road and MGE Power West Campus. They are not owned by MGE. Due to the contractual agreements for these projects with MGE, the entities are considered VIEs with respect to MGE and their results are consolidated with those of MGE, the primary beneficiary of the VIEs. The following table shows MGE Energy's noncontrolling interest, net of tax, reflected on MGE's consolidated statement of income:

		Three Months Ended
		June 30,
(In millions)		2025		2024
MGE Power Elm Road	$	3.9	$	3.9
MGE Power West Campus		1.8		1.9

Results of Operations

Six Months Ended June 30, 2025 and 2024

Electric sales and revenues

The following table compares MGE's electric revenues and electric kWh sales by customer class for each of the periods indicated:

		Revenues				Sales (kWh)
		Six Months Ended June 30,				Six Months Ended June 30,
(In thousands, except CDD)		2025		2024	% Change	2025	2024	% Change
Residential	$	88,321	$	81,462	8.4%	418,336	393,578	6.3%
Commercial		124,662		124,024	0.5%	870,250	860,943	1.1%
Industrial		6,081		6,855	(11.3)%	70,270	74,270	(5.4)%
Other-retail/municipal		19,690		20,093	(2.0)%	178,950	180,495	(0.9)%
Total retail		238,754		232,434	2.7%	1,537,806	1,509,286	1.9%
Sales to the market		14,320		2,595	n.m.	219,499	61,687	n.m.
Other revenues		1,693		1,479	14.5%	—	—	—%
Total	$	254,767	$	236,508	7.7%	1,757,305	1,570,973	11.9%
Cooling degree days (normal 208)						223	207	7.7%

n.m. not meaningful

Electric revenue increased $18.3 million during the six months ended June 30, 2025, compared to the same period in the prior year, due to the following:

(In millions)
Sales to the market	$	11.7
Rate changes		4.8
Increase in residential volume		4.3
Customer fixed and demand charges		2.4
Net increase in commercial, industrial and other-retail/municipal volume		0.6
Other		0.2
Revenue subject to refund, net		(5.7)
Total	$	18.3

•Sales to the market. Sales to the market typically occur when MGE has more generation in the MISO market than are needed for its customer demand. The excess electricity is then sold to other utilities or power marketers in the MISO market. During the six months ended June 30, 2025, market volumes increased compared to the same period in the prior year, reflecting an increase in sales. Additionally, the cost of capacity sold increased, contributing to the revenue generated from increased sales to the market from excess generation and purchases. The revenue generated from these sales is largely offset by fuel rules costs, and do not have a significant impact on net income. See fuel rules discussion in Footnote 9 of the Notes to Consolidated Financial Statements in this Report.

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•Rate changes. In December 2023, the PSCW authorized MGE to increase 2025 rates for retail electric customers by approximately 2.63%. Rates charged to retail customers during the six months ended June 30, 2025, were $4.8 million higher than those charged during the same period in the prior year. See Footnote 9 of the Notes to Consolidated Financial Statements in this Report for further information on the rate increase. Any increase in rates associated with fuel or purchase power costs are generally offset by fuel and purchased power costs and do not have a significant impact on net income.

•Volume. During the six months ended June 30, 2025, residential sales increased by approximately 6% compared to the same period in the prior year. This increase was driven by differences in the weather experienced during the six months ended June 30, 2025, compared to the same period in the prior year. Temperatures, on average, were warmer than normal in the first half of 2025.

•Customer fixed and demand charges. During the six months ended June 30, 2025, fixed and demand charges increased $2.4 million, primarily attributable to the increase in demand charges for commercial customers.

•Revenue subject to refund. For cost recovery mechanisms, any over-collection of revenues resulting from costs authorized to be collected from customers in rates exceeding actual costs is recorded as a reduction of revenue in the period incurred, as the over-collection is expected to be refunded to customers in a subsequent period. In the year the over-collection is refunded, rates are reduced and offset as revenue subject to refund. There is no net income impact in the year the costs are refunded.

Electric fuel and purchased power

	Six Months Ended June 30,
(In millions)	2025		2024		$ Change
Fuel for electric generation	$	33.9	$	23.9	$	10.0
Purchased power		9.9		18.3		(8.4)

The $10.0 million increase in fuel for electric generation in the first half of 2025 was due to an approximately 27% increase in internal generation driven by an increase in sales and 12% increase in the average cost, each compared to the same period in the prior year.

Excluding deferred fuel costs, purchased power decreased $4.3 million in the first half of 2025, compared to the same period in the prior year. The decrease in purchased power was due to an approximately 53% decrease in market purchases as a result of increased internal generation. This decrease was partially offset by an approximately 48% increase in average cost. Deferred fuel cost recovered during the six months ended June 30, 2024, was $4.1 million. There were no deferred fuel costs recovered during the six months ended June 30, 2025.

Fuel and purchased power costs are generally offset by electric revenue and do not have a significant impact on net income. MGE expects to seek and receive recovery of fuel and purchased power costs that exceed the fuel rules bandwidth in customer rates. See Footnote 9 of the Notes to Consolidated Financial Statements in this Report for further information on the fuel rules bandwidth.

Gas deliveries and revenues

The following table compares MGE's gas revenues and gas therms delivered by customer class for each of the periods indicated:

		Revenues				Therms Delivered
(In thousands, except HDD and average		Six Months Ended June 30,				Six Months Ended June 30,
rate per therm of retail customer)		2025		2024	% Change	2025	2024	% Change
Residential	$	71,824	$	58,987	21.8%	65,263	55,629	17.3%
Commercial/Industrial		47,547		37,400	27.1%	60,620	53,048	14.3%
Total retail		119,371		96,387	23.8%	125,883	108,677	15.8%
Gas transportation		3,697		3,585	3.1%	37,253	36,256	2.7%
Other revenues		338		313	8.0%	—	—	—%
Total	$	123,406	$	100,285	23.1%	163,136	144,933	12.6%
Heating degree days (normal 4,283)						4,212	3,580	17.7%
Average rate per therm of retail customer	$	0.948	$	0.887	6.9%

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Gas revenue increased $23.1 million during the six months ended June 30, 2025, compared to the same period in the prior year, due to the following:

(In millions)
Rate changes	$	13.9
Increase in volume		11.3
Other		(1.8)
Revenue subject to refund, net		(0.3)
Total	$	23.1

•Rate changes. In December 2023, the PSCW authorized MGE to increase 2025 rates for retail gas customers by approximately 1.32%.

MGE recovers the cost of natural gas in its gas segment through the purchased gas adjustment clause (PGA). Under the PGA, MGE is able to pass through to its gas customers the cost of gas. Changes in PGA recoveries affect revenues but do not change net income in view of the pass-through treatment of the costs. Payments for natural gas increased, driving higher rates during the six months ended June 30, 2025.

The average retail rate per therm excluding customer fixed charges for the six months ended June 30, 2025, increased approximately 7% compared to the same period in the prior year, reflecting an increase in natural gas commodity costs (recovered through the PGA).

•Volume. For the six months ended June 30, 2025, retail gas deliveries increased approximately 16% compared to the same period in the prior year, primarily attributable to unfavorable weather conditions in the first half of 2024.

•Other. For the six months ended June 30, 2025, other gas revenues decreased primarily related to lower residential customer fixed charges. The PSCW approved a reduction in the customer fixed charge component of the residential gas rate in the 2025 rate proceeding.

Cost of gas sold

Cost of gas sold increased $17.1 million during the six months ended June 30, 2025, compared to the same period in the prior year. Therms delivered increased approximately 16% and cost per therm increased approximately 17%. MGE recovers the cost of natural gas in its gas segment through the PGA as described under gas deliveries and revenues above.

Consolidated operations and maintenance expenses

During the six months ended June 30, 2025, operations and maintenance expenses increased $3.6 million, compared to the same period in the prior year. The following contributed to the net change:

(In millions)
Increased transmission costs	$	1.6
Increased customer services		0.9
Increased electric production expenses		0.9
Increased other expenses		0.9
Increased gas distribution expenses		0.7
Decreased administrative and general costs		(0.9)
Decreased electric distribution expenses		(0.5)
Total	$	3.6

•Increased transmission costs are primarily a result of an increase in transmission rate. Transmission costs represent ATC and MISO network transmission expenses authorized to collect in rates. The PSCW has approved MGE to defer as a regulatory asset or liability, the difference between actual costs included in rates and to be recovered or refunded in a future rate proceeding. Transmission cost is generally offset by electric revenue and does not have a significant impact on net income.

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Consolidated depreciation expense

Electric depreciation expense increased $2.1 million and gas depreciation expense increased $0.3 million during the six months ended June 30, 2025, compared to the same period in the prior year. Paris solar was placed in service in December 2024 and Darien solar was placed in service in March 2025. The timing of the in-service dates contributed to the increase in electric depreciation expense.

Electric and gas other income

Electric other income decreased $0.7 million and gas other income decreased $1.2 million during the six months ended June 30, 2025, compared to the same period in the prior year, primarily related to pension and other postretirement, excluding service costs. The PSCW has approved MGE to defer as a regulatory asset or liability, the difference between actual pension and other postretirement costs included in rates and to be recovered or refunded in a future rate proceeding. Pension and other postretirement cost is generally offset by electric and gas revenue and does not have a significant impact on net income.

Nonregulated Energy Operations - MGE Energy and MGE

The nonregulated energy operations are conducted through MGE Energy's subsidiaries: MGE Power Elm Road (the Elm Road Units) and MGE Power West Campus (WCCF), which have been formed to own and lease electric generating capacity to assist MGE. During the six months ended June 30, 2025 and 2024, net income at the nonregulated energy operations segment was $12.2 million and $11.9 million, respectively.

Transmission Investment Operations - MGE Energy

The transmission investment segment holds our interest in ATC and ATC Holdco, and its income reflects our equity in the earnings of those investments. ATC Holdco was formed in December 2016 to pursue transmission development opportunities that typically have long development and investment lead times before becoming operational. During the six months ended June 30, 2025 and 2024, other income at the transmission investment segment primarily reflects ATC's operations and was $6.2 million and $5.5 million, respectively. See Footnote 3 of the Notes to Consolidated Financial Statements in this Report for summarized financial information regarding ATC.

Consolidated Income Taxes - MGE Energy and MGE

See Footnote 4 of the Notes to Consolidated Financial Statements in this Report for the effective tax rate reconciliation.

Noncontrolling Interest, Net of Tax - MGE

Noncontrolling interest, net of tax, reflects the accounting required for MGE Energy's interest in MGE Power Elm Road (the Elm Road Units) and MGE Power West Campus (WCCF). MGE Energy owns 100% of MGE Power Elm Road and MGE Power West Campus. They are not owned by MGE. Due to the contractual agreements for these projects with MGE, the entities are considered VIEs with respect to MGE and their results are consolidated with those of MGE, the primary beneficiary of the VIEs. The following table shows MGE's noncontrolling interest, net of tax, reflected on MGE's consolidated statement of income:

	Six Months Ended
	June 30,
(In millions)	2025		2024
MGE Power Elm Road	$	7.7	$	7.7
MGE Power West Campus		3.6		3.6

Contractual Obligations and Commercial Commitments - MGE Energy and MGE

There were no material changes, other than from the normal course of business, to MGE Energy's and MGE's contractual obligations (representing cash obligations that are considered to be firm commitments) and commercial commitments (representing commitments triggered by future events) during the six months ended June 30, 2025, except as noted below. Further discussion of the contractual obligations and commercial commitments is included in Footnote 16 of the Notes to Consolidated Financial Statements and "Contractual Obligations and Commercial Commitments for MGE Energy and MGE" under Part II, Item 7, Management's Discussion and Analysis of Financial Condition and Results of Operations in the 2024 Annual Report on Form 10-K.

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Purchase Contracts – MGE Energy and MGE

See Footnote 8.c. of Notes to Consolidated Financial Statements in this Report for a description of commitments as of June 30, 2025, that MGE Energy and MGE have entered with respect to various commodity supply and transportation contracts to meet their obligations to deliver electricity and natural gas to customers.

Liquidity and Capital Resources

MGE Energy and MGE expect to have adequate liquidity to support future operations and capital expenditures over the next twelve months. Available resources include cash and cash equivalents, operating cash flows, liquid assets, borrowing working capacity under revolving credit facilities, and access to equity and debt capital markets. During the beginning of 2025, MGE Energy issued new shares of common stock to participants in our Direct Stock Purchase and Dividend Reinvestment Plan. Beginning in May 2025, MGE Energy expects to purchase shares in the open market for participants in the Direct Stock Purchase and Dividend Reinvestment Plan. MGE Energy also expects to generate funds from operations and both long-term and short-term debt financing. See "Credit Facilities" under Part II, Item 7, Management's Discussion and Analysis of Financial Condition and Results of Operations – Liquidity and Capital Resources in the 2024 Annual Report on Form 10-K for information regarding MGE Energy's and MGE's credit facilities.

Cash Flows

The following summarizes cash flows for MGE Energy and MGE during the six months ended June 30, 2025 and 2024:

	MGE Energy				MGE
(In thousands)	2025		2024		2025		2024
Cash provided by (used for):
Operating activities	$	133,953	$	130,434	$	127,988	$	128,429
Investing activities		(118,254)		(113,509)		(112,518)		(112,516)
Financing activities		(27,059)		(12,414)		(29,437)		(15,484)

Cash Provided by Operating Activities

Cash flows from operating activities for MGE Energy and MGE principally reflect the receipt of customer payments for electric and gas service and outflows related to fuel for electric generation, purchased power, gas, and operation and maintenance expenditures.

The principal increases (decreases) in cash flows from operating activities during the six months ended June 30, 2025, compared to the same period in 2024, were as follows:

(In millions)	MGE Energy		MGE
Higher overall collections from customers, driven by higher electric and gas residential sales	$	46.3	$	46.3
Higher dividend received from ATC		1.8		—
Higher payments for fuel and purchased power at our generation plants, as well as higher natural gas costs to our customers		(23.5)		(23.5)
Changes in income taxes paid/received		(8.0)		(8.9)
Higher payments for other operation and maintenance expenses		(12.4)		(14.2)
Higher payments for interest		(0.2)		(0.2)
Other operating activities		(0.5)		0.1
Increase (decrease) in cash provided by operating activities	$	3.5	$	(0.4)

Capital Requirements and Investing Activities

MGE Energy

MGE Energy's cash used for investing activities increased $4.7 million during the six months ended June 30, 2025, as compared to the same period in the prior year.

Capital expenditures during the six months ended June 30, 2025, were $111.8 million. This amount represents an increase of $0.1 million from the expenditures made in the same period in the prior year.

Capital contributions in ATC increased $2.7 million during the six months ended June 30, 2025, when compared to the same period in the prior year.

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MGE

MGE's cash used for investing activities remained flat during the six months ended June 30, 2025, when compared to the same period in the prior year.

Capital expenditures during the six months ended June 30, 2025, were $111.8 million. This amount represents an increase of $0.1 million from the expenditures made in the same period in the prior year.

Capital Expenditures

MGE Energy's and MGE's liquidity are primarily affected by their capital expenditure requirements. During the three months ended June 30, 2025, capital expenditures for MGE Energy and MGE totaled $111.8 million, which included $106.0 million of utility capital expenditures. Utility capital expenditures include investments in renewable generation and battery storage facilities, such as the Koshkonong and High Noon projects.

MGE does not currently expect any material changes to its total forecasted expenditures as presented in the 2025 through 2029 capital expenditure forecast included under Part II, Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations – Liquidity and Capital Resources in the 2024 Annual Report on Form 10-K. MGE's plan to achieve its target of 80% carbon reduction by 2030 (from 2005 levels) is based on the transition away from coal, addition of new renewable generation, and additional generation sources that provide the reliable energy to serve demand dependably. The mix of generation sources presented in the 2025 through 2029 capital expenditure forecast may shift based on reliability needs as MGE continues on the path to achieve its carbon reduction goals. Additionally, MGE is monitoring a range of regulatory and trade policy developments that may affect solar project timelines and costs, including import regulations under the Uyghur Forced Labor Prevention Act, solar tariffs administered by the U.S. Department of Commerce, tariffs issued through executive orders, and potential impacts related to the OBBBA. These disruptions have impacted and may continue to impact current and future solar projects by increasing costs or causing delays in construction timelines. As projects are delayed, timing of capital expenditures will be correspondingly shifted. See "Other Matters" below for additional information on the solar procurement disruptions.

Cash Used for Financing Activities

The principal sources and uses of cash are related to short-term and long-term borrowings and repayments and the payment of cash dividends.

The principal increases (decreases) in cash flows from financing activities during the six months ended June 30, 2025, compared to the same period in 2024, were as follows:

(In millions)	MGE Energy		MGE
Issuance of common stock	$	3.8	$	—
Higher cash dividends paid, dividend rate per share ($0.900 vs. $0.855)		(1.9)		—
Lower cash dividends to parent (MGE Energy)		—		0.5
Lower distributions to parent (MGE Energy) from noncontrolling interest, representing distributions from MGE Power Elm Road and MGE Power West Campus(a)		—		2.0
Change in long-term debt		(0.1)		(0.1)
Change in short-term debt borrowings, net		(16.3)		(16.3)
Other financing activities		(0.1)		(0.1)
Decrease in cash flows from financing activities	$	(14.6)	$	(14.0)

(a)The noncontrolling interest arises from the accounting required for the entities, which are not owned by MGE but are consolidated as VIEs.

Capitalization Ratios

MGE Energy's capitalization ratios were as follows:

	MGE Energy
	June 30, 2025	December 31, 2024
Common shareholders' equity	62.2%	61.5%
Long-term debt(a)	37.5%	38.5%
Short-term debt	0.3%	—%

(a)Includes the current portion of long-term debt.

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Credit Ratings

MGE Energy's and MGE's access to the capital markets, including, in the case of MGE, the commercial paper market, and their respective financing costs in those markets, may depend on the credit ratings of the entity that is accessing the capital markets.

None of MGE Energy's or MGE's borrowing is subject to default or prepayment as a result of a downgrading of credit ratings, although a downgrading of MGE's credit ratings would increase fees and interest charges under both MGE Energy's and MGE's credit agreements and may affect the collateral required to be posted under derivative transactions.

Environmental Matters

In March 2025, the EPA announced its intention to initiate regulatory actions concerning several key environmental regulations, including the 2024 power plant greenhouse gas regulations, Effluent Limitation Guidelines, the 2024 amendments to the CCR Rule, and the 2023 Good Neighbor Plan. See Footnote 8.a. of Notes to Consolidated Financial Statements in this Report for additional details on where the EPA has taken regulatory action or similar formal steps since making the announcement. MGE is closely monitoring the EPA's administrative efforts in these areas and will evaluate appropriate responses as developments occur.

See the discussion of environmental matters included in the 2024 Annual Report on Form 10-K, as updated by Footnote 8.a. of Notes to Consolidated Financial Statements in this Report.

Other Matters

Rate Matters

In December 2023, the PSCW approved the 2024/2025 rate application for a 4.17% increase for electric rates and a 1.32% increase to gas rates for 2025. The PSCW approved a 2025 Fuel Cost Plan in December 2024. The plan lowered the 2025 increase in electric rates to 2.63%.

In April 2025, MGE filed a 2026/2027 rate application with a proposed increase of 4.89% for electric rates and a 2.33% increase for gas rates in 2026. The application addresses rates for 2027 proposing a 4.33% increase for electric rates and a 2.16% increase to gas rates for 2027. PSCW approval is pending. A final order is expected before the end of the year.

Details related to MGE's 2024/2025 approved rate proceeding and 2026/2027 proposed rate proceeding are as follows:

(Dollars in thousands)	Average Rate Base(a)		Average CWIP(b)		Return on Common Equity(c)	Common Equity Component of Regulatory Capital Structure	Effective Date
Electric (2025 Test Period)	$	1,241,502	$	7,106	9.7%	56.06%	1/1/2025
Gas (2025 Test Period)	$	341,369	$	7,146	9.7%	56.06%	1/1/2025
Electric (2026 Test Period)(d)	$	1,362,320	$	34,666	10.0%	56.08%	1/1/2026
Gas (2026 Test Period)(d)	$	378,582	$	6,053	10.0%	56.08%	1/1/2026
Electric (2027 Test Period)(d)	$	1,549,683	$	29,151	10.0%	56.04%	1/1/2027
Gas (2027 Test Period)(d)	$	399,304	$	6,291	10.0%	56.04%	1/1/2027

(a)Average rate base amounts reflect MGE's allocated share of rate base and do not include construction work in progress (CWIP) or a cash working capital allowance and were calculated using a forecasted 13-month average for the test periods. The PSCW provides a return on selected CWIP and a cash working capital allowance by adjusting the percentage return on rate base.

(b)50% of the forecasted 13-month average CWIP for the test periods earns an AFUDC return. Projects eligible to earn 100% AFUDC are excluded from this balance and discussed further in the Management Discussion and Analysis of Financial Condition and Results of Operations - Significant Events section.

(c)Returns on common equity may not be indicative of actual returns earned or projections of future returns, as actual returns will be affected by the volume of electricity or gas sold.

(d)Pending approval by the PSCW.

See Footnote 9 of Notes to Consolidated Financial Statements in this Report for further discussion of rate proceedings and an earnings sharing mechanism if MGE earns above the authorized return on common equity in the rate order.

44

Uyghur Forced Labor Protection Act

In June 2021, the U.S. Customs and Border Protection (CBP) issued a Withhold Release Order (WRO) against silica-based products made by Hoshine Silicon Industry Co. Ltd., a company located in China's Xinjiang Uyghur Autonomous Region. The WRO was superseded by the Uyghur Forced Labor Protection Act (UFLPA), a federal law that became effective on June 21, 2022, which further established that all goods mined, produced, or manufactured wholly or in part in Xinjiang or by certain defined entities are prohibited from U.S. importation. Suppliers for MGE's current solar projects were able to provide the CBP sufficient documentation to meet WRO and UFLPA compliance requirements, however we cannot currently predict what, if any, impact the UFLPA will have on the overall supply of solar panels into the United States and the related impact to timing and cost of solar projects included in our capital plan. In the event that such disruptions cause costs to exceed the levels approved for specific projects, we have filed and expect to continue to file a notification with the PSCW and expect to request recovery of any cost increases in MGE's future rate proceedings.

In January 2025, several more Chinese companies, including five solar supply chain providers, were banned under the UFLPA. MGE continues to ensure its compliance with the UFLPA.

U.S. Department of Commerce - Solar Cells and Modules

In August 2023, the U.S. Department of Commerce issued its final determination on a solar tariff investigation that began in 2022, finding that Chinese manufacturers were circumventing tariffs on solar panels by shipping them through four Southeast Asian countries. A 24-month exemption from tariffs for solar panel and module imports from these four countries was in effect from June 2022 until June 6, 2024. In May 2024, the Biden Administration announced that bifacial solar panels would be subject to safeguard tariffs under Section 201 of the Trade Act of 1974, from which they were previously excluded. President Biden also directed U.S. Trade Representatives to increase tariffs under Section 301 from 25% to 50% on solar cells and modules. This change went into effect in September 2024. In April 2025, the U.S. Department of Commerce issued final determinations indicating that panel cells imported from Cambodia, Malaysia, Thailand, and Vietnam are being unfairly traded. The U.S. International Trade Commission issued a final injury ruling in favor of the tariffs, which went into effect in June 2025. MGE continues to assess the potential impact of these tariffs on current and future solar projects which may result in an increase in costs or delays in construction timelines. In the event that such disruptions cause costs to exceed the levels approved for specific projects, we have filed and expect to continue to file a notification with the PSCW and expect to request recovery of any cost increases in MGE's future rate proceedings.

Tariffs

U.S. and international trade policies, including tariffs, port fees, trade sanctions, and other import/export regulations, continue to evolve, influenced by geopolitical developments and economic priorities. MGE is proactively evaluating the potential effects of these changes on operating costs and capital investments, particularly for renewable energy and battery storage initiatives. Such policy shifts could lead to higher costs or delays in project timelines.

Tax Update - One Big Beautiful Bill Act

On July 4, 2025, the One Big Beautiful Bill Act (OBBBA) was signed into law, introducing significant changes to tax credits and compliance requirements. The OBBBA accelerates the termination of the Clean Electricity Production Tax Credit (PTC) and Clean Electricity Investment Tax Credit (ITC) for wind and solar projects placed in service after December 31, 2027, unless construction begins by July 4, 2026. The phase out of PTCs and ITCs does not apply to energy storage, hydroelectric facilities, nuclear, or any other zero emission technology. The OBBBA imposes stringent restrictions on tax credit eligibility, disallowing credits, and other provisions for projects involving material assistance from specified foreign entities or foreign-influenced entities for projects that begin construction after December 31, 2025. Additionally, the bill increases domestic content requirements, mandating that 45% of project components (by cost) be U.S.-sourced in 2025, rising to 55% by 2027. The OBBBA's implementation depends on forthcoming Treasury Department guidance as directed under the Executive Order issued on July 7, 2025, particularly regarding the definitions of "begin construction," Foreign Entity of Concern compliance, and domestic content certification processes. The lack of clarity on these definitions introduces significant uncertainty in the ability to secure tax credits for projects in development. MGE continues to evaluate the impact of the OBBBA and is closely monitoring Treasury Department updates and engaging with industry groups to ensure compliance.

Adoption of Accounting Principles and Recently Issued Accounting Pronouncements

See Footnote 2 of Notes to Consolidated Financial Statements in this Report for discussion of new accounting pronouncements.

45

Item 3. Quantitative and Qualitative Disclosures About Market Risk.

There were no material changes to the market risks disclosed in Item 7A. Quantitative and Qualitative Disclosures About Market Risk in our 2024 Annual Report on Form 10-K, except as noted below.

Equity Price Risk - Pension-Related Assets

MGE currently funds its liabilities related to employee benefits through trust funds. These funds, which include investments in debt and equity securities, are managed by various third-party investment managers. Changes in the market value of these investments can have an impact on the future expenses related to these liabilities. The value of employee benefit plan assets increased by approximately 7% during the six months ended June 30, 2025.

Item 4. Controls and Procedures.

During the second quarter of 2025, each registrant's management, including the principal executive officer and principal financial officer, evaluated its disclosure controls and procedures related to the recording, processing, summarization, and reporting of information in its periodic reports that it files with the SEC. These disclosure controls and procedures have been designed to ensure that material information relating to that registrant, including its subsidiaries, is accumulated and made known to that registrant's management, including these officers, by other employees of that registrant and its subsidiaries as appropriate to allow timely decisions regarding required disclosure, and that this information is recorded, processed, summarized, evaluated, and reported, as applicable, within the time periods specified in the SEC's rules and forms. The evaluations take into account changes in the internal and external operating environments that may impact those controls and procedures. Due to the inherent limitations of control systems, not all misstatements may be detected. These inherent limitations include the realities that judgments in decision making can be faulty and breakdowns can occur because of simple error or mistake. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people, or by management override of the control. Also, MGE Energy does not control or manage certain of its unconsolidated entities and thus, its access and ability to apply its procedures to those entities is more limited than is the case for its consolidated subsidiaries.

As of June 30, 2025, each registrant's principal executive officer and principal financial officer concluded that its disclosure controls and procedures were effective. Each registrant intends to strive continually to improve its disclosure controls and procedures to enhance the quality of its financial reporting.

During the quarter ended June 30, 2025, there were no changes in either registrant's internal controls over financial reporting that materially affected, or are reasonably likely to affect materially, that registrant's internal control over financial reporting.

46

PART II. OTHER INFORMATION.

Item 1. Legal Proceedings.

MGE Energy and its subsidiaries, including MGE, from time to time are involved in various legal proceedings that are handled and defended in the ordinary course of business. See Footnotes 8.a. and 8.b. of Notes to Consolidated Financial Statements in this Report for more information.

Item 1A. Risk Factors.

There were no material changes from the risk factors disclosed in Item 1A. Risk Factors in our 2024 Annual Report on Form 10-K.

Item 2. Unregistered Sales of Equity Securities and Use of Proceeds.

Under the MGE Energy, Inc. Stock Plan, common stock shares purchased by plan participants may be either shares issued by MGE Energy or shares purchased on the open market, as determined from time to time by MGE Energy. Shares issued by MGE Energy are covered by an existing registration statement. Shares purchased in the open market are purchased at the direction of the plan participants by MGE Energy's transfer agent's securities broker-dealer for the accounts of those plan participants. Subject to the plan's restrictions, the timing and amount of open market purchases is determined by the plan participants and the broker-dealer. MGE Energy is not involved in the open market purchases. During the beginning of 2025, MGE Energy issued new shares of common stock to participants in its Direct Stock Purchase and Dividend Reinvestment Plan. MGE Energy began purchasing shares in the open market starting in May 2025.

Item 3. Defaults Upon Senior Securities.

None.

Item 4. Mine Safety Disclosures.

Not applicable to MGE Energy and MGE.

Item 5. Other Information.

During the three months ended June 30, 2025, no director or officer of MGE Energy or MGE adopted or terminated a Rule 10b5-1 trading arrangement or non-Rule 10b5-1 trading arrangement, as each term is defined in Item 408(a) of Regulation S-K.

47

Item 6. Exhibits.

Ex. No.		Exhibit Description
31.1	*	Certifications Pursuant to Rule 13a-14(a) and 15d-14(a) of the Securities Exchange Act of 1934 filed by Jeffrey M. Keebler for MGE Energy, Inc.
31.2	*	Certifications Pursuant to Rule 13a-14(a) and 15d-14(a) of the Securities Exchange Act of 1934 filed by Jared J. Bushek for MGE Energy, Inc.
31.3	*	Certifications Pursuant to Rule 13a-14(a) and 15d-14(a) of the Securities Exchange Act of 1934 filed by Jeffrey M. Keebler for Madison Gas and Electric Company
31.4	*	Certifications Pursuant to Rule 13a-14(a) and 15d-14(a) of the Securities Exchange Act of 1934 filed by Jared J. Bushek for Madison Gas and Electric Company
32.1	**	Certifications Pursuant to Section 1350 of Chapter 63 of Title 18 United States Code (Sarbanes-Oxley Act of 2002) filed by Jeffrey M. Keebler for MGE Energy, Inc.
32.2	**	Certifications Pursuant to Section 1350 of Chapter 63 of Title 18 United States Code (Sarbanes-Oxley Act of 2002) filed by Jared J. Bushek for MGE Energy, Inc.
32.3	**	Certifications Pursuant to Section 1350 of Chapter 63 of Title 18 United States Code (Sarbanes-Oxley Act of 2002) filed by Jeffrey M. Keebler for Madison Gas and Electric Company
32.4	**	Certifications Pursuant to Section 1350 of Chapter 63 of Title 18 United States Code (Sarbanes-Oxley Act of 2002) filed by Jared J. Bushek for Madison Gas and Electric Company
101.INS	*	XBRL Instance
101.SCH	*	XBRL Taxonomy Extension Schema With Embedded Linkbases Document
104.1	*	Included in the cover page, formatted in Inline XBRL
*		Filed herewith.
**		Furnished herewith.

48

Signatures - MGE Energy, Inc.

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	MGE ENERGY, INC.
Date: August 6, 2025	/s/ Jeffrey M. Keebler
	Jeffrey M. Keebler Chairman, President and Chief Executive Officer (Duly Authorized Officer)
Date: August 6, 2025	/s/ Jared J. Bushek
	Jared J. Bushek Vice President - Chief Financial Officer and Treasurer (Chief Financial Officer)
Date: August 6, 2025	/s/ Jenny L. Lagerwall
	Jenny L. Lagerwall Assistant Vice President - Accounting and Controller (Chief Accounting Officer)

49

Signatures – Madison Gas and Electric Company

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

	MADISON GAS AND ELECTRIC COMPANY
Date: August 6, 2025	/s/ Jeffrey M. Keebler
	Jeffrey M. Keebler Chairman, President and Chief Executive Officer (Duly Authorized Officer)
Date: August 6, 2025	/s/ Jared J. Bushek
	Jared J. Bushek Vice President - Chief Financial Officer and Treasurer (Chief Financial Officer)
Date: August 6, 2025	/s/ Jenny L. Lagerwall
	Jenny L. Lagerwall Assistant Vice President - Accounting and Controller (Chief Accounting Officer)

50

EX-31.1

EXHIBIT 31.1

Certification Pursuant to Rule 13a-14(a) and 15d-14(a) of the Securities Exchange Act of 1934

I, Jeffrey M. Keebler, certify that:

1.I have reviewed this quarterly report on Form 10-Q of MGE Energy, Inc.;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5.The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

(a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

(b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

/s/ Jeffrey M. Keebler

Jeffrey M. Keebler

Chairman, President and Chief Executive Officer

Date: August 6, 2025

1

EX-31.2

EXHIBIT 31.2

Certification Pursuant to Rule 13a-14(a) and 15d-14(a) of the Securities Exchange Act of 1934

I, Jared J. Bushek, certify that:

1.I have reviewed this quarterly report on Form 10-Q of MGE Energy, Inc.;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5.The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

(a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

(b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

/s/ Jared J. Bushek

Jared J. Bushek

Vice President - Chief Financial Officer and Treasurer

Date: August 6, 2025

1

EX-31.3

EXHIBIT 31.3

Certification Pursuant to Rule 13a-14(a) and 15d-14(a) of the Securities Exchange Act of 1934

I, Jeffrey M. Keebler, certify that:

1.I have reviewed this quarterly report on Form 10-Q of Madison Gas and Electric Company;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5.The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

(a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

(b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

/s/ Jeffrey M. Keebler

Jeffrey M. Keebler

Chairman, President and Chief Executive Officer

Date: August 6, 2025

1

EX-31.4

EXHIBIT 31.4

Certification Pursuant to Rule 13a-14(a) and 15d-14(a) of the Securities Exchange Act of 1934

I, Jared J. Bushek, certify that:

1.I have reviewed this quarterly report on Form 10-Q of Madison Gas and Electric Company;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

(a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)Evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)Disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting; and

5.The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of the registrant's board of directors (or persons performing the equivalent functions):

(a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

(b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

/s/ Jared J. Bushek

Jared J. Bushek

Vice President - Chief Financial Officer and Treasurer

Date: August 6, 2025

1

EX-32.1

EXHIBIT 32.1

Certification Pursuant to 18 U.S.C. Section 1350,

as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the quarterly report on Form 10-Q of MGE Energy, Inc. (the "Company"), for the period ended June 30, 2025, as filed with the Securities and Exchange Commission on the date hereof ("the Report"), I, Jeffrey M. Keebler, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1.The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and

2.The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Jeffrey M. Keebler

Jeffrey M. Keebler

Chairman, President and Chief Executive Officer

Date: August 6, 2025

1

EX-32.2

EXHIBIT 32.2

Certification Pursuant to 18 U.S.C. Section 1350,

as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the quarterly report on Form 10-Q of MGE Energy, Inc. (the "Company"), for the period ended June 30, 2025, as filed with the Securities and Exchange Commission on the date hereof ("the Report"), I, Jared J. Bushek, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1.The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and

2.The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Jared J. Bushek

Jared J. Bushek

Vice President - Chief Financial Officer and Treasurer

Date: August 6, 2025

1

EX-32.3

EXHIBIT 32.3

Certification Pursuant to 18 U.S.C. Section 1350,

as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the quarterly report on Form 10-Q of Madison Gas and Electric Company (the "Company"), for the period ended June 30, 2025, as filed with the Securities and Exchange Commission on the date hereof ("the Report"), I, Jeffrey M. Keebler, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1.The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and

2.The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Jeffrey M. Keebler

Jeffrey M. Keebler

Chairman, President and Chief Executive Officer

Date: August 6, 2025

1

EX-32.4

EXHIBIT 32.4

Certification Pursuant to 18 U.S.C. Section 1350,

as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002

In connection with the quarterly report on Form 10-Q of Madison Gas and Electric Company (the "Company"), for the period ended June 30, 2025, as filed with the Securities and Exchange Commission on the date hereof ("the Report"), I, Jared J. Bushek, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

1.The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and

2.The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

/s/ Jared J. Bushek

Jared J. Bushek

Vice President - Chief Financial Officer and Treasurer

Date: August 6, 2025

1

XML

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2025	Jul. 31, 2025
Document And Entity Information [Line Items]
Entity Registrant Name	MGE Energy, Inc.
Entity Central Index Key	0001161728
Document Type	10-Q
Document Period End Date	Jun. 30, 2025
Amendment Flag	false
Trading Symbol	MGEE
Document Fiscal Year Focus	2025
Document Fiscal Period Focus	Q2
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		36,541,849
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Security Exchange Name	NASDAQ
Security 12(b) Title	Common Stock, $1 Par Value Per Share
Entity Tax Identification Number	39-2040501
Securities Act File Number	000-49965
Entity Incorporation, State or Country Code	WI
Entity Address, Address Line One	133 South Blair Street
Entity Address, City or Town	Madison
Entity Address, State or Province	WI
Entity Address, Postal Zip Code	53788
City Area Code	608
Local Phone Number	252-7000
Document Transition Report	false
Entity Interactive Data Current	Yes
Document Quarterly Report	true
MGE [Member]
Document And Entity Information [Line Items]
Entity Registrant Name	Madison Gas and Electric Company
Entity Central Index Key	0000061339
Entity Current Reporting Status	Yes
Entity Filer Category	Non-accelerated Filer
Entity Common Stock, Shares Outstanding		17,347,894
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Tax Identification Number	39-0444025
Securities Act File Number	000-1125
Entity Incorporation, State or Country Code	WI
Entity Address, Address Line One	133 South Blair Street
Entity Address, City or Town	Madison
Entity Address, State or Province	WI
Entity Address, Postal Zip Code	53788
City Area Code	608
Local Phone Number	252-7000
Document Transition Report	false
Entity Interactive Data Current	Yes
Document Quarterly Report	true

XML

Consolidated Statements of Income (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Operating Revenues:
Electric revenues	$ 129,527	$ 120,597	$ 255,016	$ 236,764
Gas revenue	29,925	25,116	123,406	100,285
Total Operating Revenues	159,452	145,713	378,422	337,049
Operating Expenses:
Fuel for electric generation	16,292	11,237	33,861	23,941
Purchased power	5,562	8,850	9,940	18,292
Cost of gas sold	11,313	6,293	65,277	48,170
Other operations and maintenance	57,777	56,730	114,336	110,704
Depreciation and amortization	28,354	26,932	56,032	53,532
Other general taxes	5,931	5,936	11,888	11,930
Total Operating Expenses	125,229	115,978	291,334	266,569
Operating Income	34,223	29,735	87,088	70,480
Other income, net	3,707	3,856	6,311	7,737
Interest expense, net	(8,457)	(8,325)	(16,038)	(16,329)
Income before income taxes	29,473	25,266	77,361	61,888
Income tax provision	(2,975)	(1,472)	(9,271)	(4,280)
Net Income Including Noncontrolling Interest	26,498	23,794	68,090	57,608
Net Income	$ 26,498	$ 23,794	$ 68,090	$ 57,608
Earnings per share of Common Stock - Basic	$ 0.73	$ 0.66	$ 1.86	$ 1.59
Earnings per share of Common Stock - Diluted	0.72	0.66	1.86	1.59
Dividends per share of common stock	$ 0.45	$ 0.428	$ 0.9	$ 0.855
Weighted Average Shares Outstanding - Basic	36,540	36,176	36,526	36,173
Weighted Average Shares Outstanding - Diluted	36,569	36,197	36,557	36,196
MGE [Member]
Operating Revenues:
Electric revenues	$ 129,527	$ 120,597	$ 255,016	$ 236,764
Gas revenue	29,925	25,116	123,406	100,285
Total Operating Revenues	159,452	145,713	378,422	337,049
Operating Expenses:
Fuel for electric generation	16,292	11,237	33,861	23,941
Purchased power	5,562	8,850	9,940	18,292
Cost of gas sold	11,313	6,293	65,277	48,170
Other operations and maintenance	57,489	56,601	113,751	110,161
Depreciation and amortization	28,354	26,932	56,032	53,532
Other general taxes	5,931	5,936	11,888	11,930
Total Operating Expenses	124,941	115,849	290,749	266,026
Operating Income	34,511	29,864	87,673	71,023
Other income, net	747	1,134	363	2,242
Interest expense, net	(8,554)	(8,433)	(16,189)	(16,509)
Income before income taxes	26,704	22,565	71,847	56,756
Income tax provision	(2,229)	(811)	(7,569)	(2,802)
Net Income Including Noncontrolling Interest	24,475	21,754	64,278	53,954
Less Net Income Attributable to Noncontrolling Interest, net of tax	(5,714)	(5,766)	(11,313)	(11,363)
Net Income	$ 18,761	$ 15,988	$ 52,965	$ 42,591

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Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Operating Activities:
Net Income	$ 68,090	$ 57,608
Items not affecting cash:
Depreciation and amortization	56,032	53,532
Deferred income taxes	2,578	(1,351)
Provision for doubtful receivables	4,400	4,400
Employee benefit plan (credit) cost	(2,320)	323
Equity earnings in investments	(6,241)	(5,526)
Other items	378	930
Changes in working capital items:
Current assets	13,446	22,086
Accounts payable	(13,491)	(9,646)
Other current liabilities	1,298	3,718
Dividends from investments	6,008	4,238
Cash contributions to pension and other postretirement plans	(3,800)	(3,634)
Other noncurrent items, net	7,575	3,756
Cash Provided by Operating Activities	133,953	130,434
Investing Activities:
Capital expenditures	(111,753)	(111,622)
Capital contributions to investments	(5,871)	(3,159)
Other	(630)	1,272
Cash Used for Investing Activities	(118,254)	(113,509)
Financing Activities:
Issuance of common stock, net	3,750	0
Cash dividends paid on common stock	(32,872)	(30,930)
Repayments of long-term debt	(2,625)	(2,556)
Proceeds from short-term debt	5,500	21,800
Other	(812)	(728)
Cash Used for Financing Activities	(27,059)	(12,414)
Change in cash, cash equivalents, and restricted cash	(11,360)	4,511
Cash, cash equivalents, and restricted cash at beginning of period	24,496	15,026
Cash, cash equivalents, and restricted cash at end of period	13,136	19,537
Significant noncash investing activities:
Accrued capital expenditures	9,120	11,416
MGE [Member]
Operating Activities:
Net Income	64,278	53,954
Items not affecting cash:
Depreciation and amortization	56,032	53,532
Deferred income taxes	1,785	(1,287)
Provision for doubtful receivables	4,400	4,400
Employee benefit plan (credit) cost	(2,319)	323
Other items	766	1,446
Changes in working capital items:
Current assets	13,448	22,098
Accounts payable	(13,533)	(9,642)
Other current liabilities	836	4,774
Cash contributions to pension and other postretirement plans	(3,800)	(3,634)
Other noncurrent items, net	6,095	2,465
Cash Provided by Operating Activities	127,988	128,429
Investing Activities:
Capital expenditures	(111,753)	(111,622)
Other	(765)	(894)
Cash Used for Investing Activities	(112,518)	(112,516)
Financing Activities:
Cash dividends paid to parent by MGE	(23,500)	(24,000)
Distributions to parent from noncontrolling interest	(8,000)	(10,000)
Repayments of long-term debt	(2,625)	(2,556)
Proceeds from short-term debt	5,500	21,800
Other	(812)	(728)
Cash Used for Financing Activities	(29,437)	(15,484)
Change in cash, cash equivalents, and restricted cash	(13,967)	429
Cash, cash equivalents, and restricted cash at beginning of period	20,059	6,705
Cash, cash equivalents, and restricted cash at end of period	6,092	7,134
Significant noncash investing activities:
Accrued capital expenditures	$ 9,120	$ 11,416

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Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Current Assets:
Cash and cash equivalents	$ 10,569	$ 21,302
Accounts receivable, less reserves	43,308	51,277
Other accounts receivables, less reserves	10,239	10,067
Unbilled revenues	29,815	35,833
Materials and supplies, at average cost	37,958	36,187
Fuel for electric generation, at average cost	11,706	11,521
Stored natural gas, at average cost	16,543	19,937
Prepaid taxes	17,946	18,390
Regulatory assets - current	6,317	8,522
Other current assets	13,851	14,229
Total Current Assets	198,252	227,265
Regulatory assets	41,313	36,764
Pension benefit asset	138,063	132,264
Other deferred assets and other	18,505	26,285
Property, Plant, and Equipment:
Property, plant, and equipment, net	2,238,086	2,149,138
Construction work in progress	102,648	138,208
Total Property, Plant, and Equipment	2,340,734	2,287,346
Investments	123,670	118,035
Total Assets	2,860,537	2,827,959
Current Liabilities:
Long-term debt due within one year	5,358	5,285
Short-term debt	5,500	0
Accounts payable	50,344	77,466
Accrued interest and taxes	10,048	11,558
Accrued payroll related items	13,696	15,870
Regulatory liabilities - current	15,812	7,966
Other current liabilities	9,079	7,418
Total Current Liabilities	109,837	125,563
Other Credits:
Deferred income taxes	316,017	316,397
Investment tax credit - deferred	49,702	44,988
Regulatory liabilities	164,177	163,336
Accrued pension and other postretirement benefits	50,583	50,155
Asset retirement obligations	73,739	69,132
Other deferred liabilities and other	65,235	64,553
Total Other Credits	719,453	708,561
Capitalization:
Common shareholders equity	1,269,973	1,230,138
Long-term debt	761,274	763,697
Total Capitalization	2,031,247	1,993,835
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	2,860,537	2,827,959
MGE [Member]
Current Assets:
Cash and cash equivalents	3,525	16,865
Accounts receivable, less reserves	43,308	51,277
Other accounts receivables, less reserves	10,235	10,063
Unbilled revenues	29,815	35,833
Materials and supplies, at average cost	37,958	36,187
Fuel for electric generation, at average cost	11,706	11,521
Stored natural gas, at average cost	16,543	19,937
Prepaid taxes	17,938	18,359
Regulatory assets - current	6,317	8,522
Other current assets	14,336	14,740
Total Current Assets	191,681	223,304
Regulatory assets	41,313	36,764
Pension benefit asset	138,063	132,264
Other deferred assets and other	17,921	25,690
Property, Plant, and Equipment:
Property, plant, and equipment, net	2,238,114	2,149,165
Construction work in progress	102,648	138,208
Total Property, Plant, and Equipment	2,340,762	2,287,373
Total Assets	2,729,740	2,705,395
Current Liabilities:
Long-term debt due within one year	5,358	5,285
Short-term debt	5,500	0
Accounts payable	50,288	77,453
Accrued interest and taxes	9,885	11,866
Accrued payroll related items	13,696	15,870
Regulatory liabilities - current	15,812	7,966
Other current liabilities	9,087	7,418
Total Current Liabilities	109,626	125,858
Other Credits:
Deferred income taxes	279,789	280,961
Investment tax credit - deferred	49,702	44,988
Regulatory liabilities	164,177	163,336
Accrued pension and other postretirement benefits	50,583	50,155
Asset retirement obligations	73,739	69,132
Other deferred liabilities and other	68,267	67,463
Total Other Credits	686,257	676,035
Capitalization:
Common shareholders equity	1,018,884	989,419
Noncontrolling interest	153,699	150,386
Total Equity	1,172,583	1,139,805
Long-term debt	761,274	763,697
Total Capitalization	1,933,857	1,903,502
Commitments and contingencies (see Footnote 8)
Total Liabilities and Capitalization	$ 2,729,740	$ 2,705,395

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Consolidated Balance Sheets (Unaudited) (Parentheticals) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024
Receivables, Net
Reserve for uncollectible accounts receivable	$ 8,586	$ 6,905
Reserve for uncollectible other accounts receivable	2,042	2,124
MGE [Member]
Receivables, Net
Reserve for uncollectible accounts receivable	8,586	6,905
Reserve for uncollectible other accounts receivable	$ 2,042	$ 2,124

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MGE Energy Inc Consolidated Statements of Common Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]
Beginning balance, shares at Dec. 31, 2023		36,163,000
Beginning balance, value at Dec. 31, 2023	$ 1,140,073	$ 36,163	$ 396,750	$ 707,160	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	57,608			57,608
Common stock dividends declared	(30,930)			(30,930)
Equity-based compensation plans and other - Shares		13,000
Issuance of common stock, net	0
Equity-based compensation plans and other	877	$ 13	864
Ending balance, shares at Jun. 30, 2024		36,176,000
Ending balance, value at Jun. 30, 2024	1,167,628	$ 36,176	397,614	733,838	0
Beginning balance, shares at Mar. 31, 2024		36,176,000
Beginning balance, value at Mar. 31, 2024	1,158,783	$ 36,176	397,093	725,514	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	23,794			23,794
Common stock dividends declared	(15,470)			(15,470)
Equity-based compensation plans and other	521		521
Ending balance, shares at Jun. 30, 2024		36,176,000
Ending balance, value at Jun. 30, 2024	1,167,628	$ 36,176	397,614	733,838	0
Beginning balance, shares at Dec. 31, 2024		36,490,000
Beginning balance, value at Dec. 31, 2024	1,230,138	$ 36,490	429,515	764,133	0
Ending balance, shares at Mar. 31, 2025		36,537,000
Ending balance, value at Mar. 31, 2025	1,258,913	$ 36,537	433,079	789,297	0
Beginning balance, shares at Dec. 31, 2024		36,490,000
Beginning balance, value at Dec. 31, 2024	1,230,138	$ 36,490	429,515	764,133	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	68,090			68,090
Common stock dividends declared	$ (32,872)			(32,872)
Stock Issued During Period, Shares, Dividend Reinvestment Plan	40,995	41,000
Stock Issued During Period, Value, Dividend Reinvestment Plan	$ 3,750	$ 41	3,709
Equity-based compensation plans and other - Shares		11,000
Issuance of common stock, net	3,750
Equity-based compensation plans and other	867	$ 11	856
Ending balance, shares at Jun. 30, 2025		36,542,000
Ending balance, value at Jun. 30, 2025	1,269,973	$ 36,542	434,080	799,351	0
Beginning balance, shares at Mar. 31, 2025		36,537,000
Beginning balance, value at Mar. 31, 2025	1,258,913	$ 36,537	433,079	789,297	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income (Loss)	26,498			26,498
Common stock dividends declared	(16,444)			(16,444)
Stock Issued During Period, Shares, Dividend Reinvestment Plan		5,000
Stock Issued During Period, Value, Dividend Reinvestment Plan	471	$ 5	466
Equity-based compensation plans and other	(535)		(535)
Ending balance, shares at Jun. 30, 2025		36,542,000
Ending balance, value at Jun. 30, 2025	$ 1,269,973	$ 36,542	$ 434,080	$ 799,351	$ 0

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Consolidated Statements of Common Equity (Unaudited) (Parentheticals) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Dividends per share of common stock	$ 0.45	$ 0.428	$ 0.9	$ 0.855

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Madison Gas and Electric Company Consolidated Statements of Common Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	MGE [Member]	Common Stock [Member]	Common Stock [Member] MGE [Member]	Additional Paid-in Capital [Member] MGE [Member]	Retained Earnings [Member] MGE [Member]	Accumulated Other Comprehensive Income/(Loss) [Member] MGE [Member]	Noncontrolling Interest [Member] MGE [Member]
Beginning balance, shares at Dec. 31, 2023			36,163	17,348
Beginning balance, value at Dec. 31, 2023		$ 1,053,256		$ 17,348	$ 252,917	$ 633,460	$ 0	$ 149,531
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	$ 57,608	53,954				42,591		11,363
Cash dividends paid to parent by MGE		(24,000)				(24,000)
Distributions to parent from noncontrolling interest		(10,000)						(10,000)
Ending balance, shares at Jun. 30, 2024			36,176	17,348
Ending balance, value at Jun. 30, 2024		1,073,210		$ 17,348	252,917	652,051	0	150,894
Beginning balance, shares at Mar. 31, 2024			36,176	17,348
Beginning balance, value at Mar. 31, 2024		1,067,456		$ 17,348	252,917	646,063	0	151,128
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	23,794	21,754				15,988		5,766
Cash dividends paid to parent by MGE		(10,000)				(10,000)
Distributions to parent from noncontrolling interest		(6,000)						(6,000)
Ending balance, shares at Jun. 30, 2024			36,176	17,348
Ending balance, value at Jun. 30, 2024		1,073,210		$ 17,348	252,917	652,051	0	150,894
Beginning balance, shares at Dec. 31, 2024			36,490	17,348
Beginning balance, value at Dec. 31, 2024		1,139,805		$ 17,348	283,667	688,404	0	150,386
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	68,090	64,278				52,965		11,313
Cash dividends paid to parent by MGE		(23,500)				(23,500)
Distributions to parent from noncontrolling interest		(8,000)						(8,000)
Ending balance, shares at Jun. 30, 2025			36,542	17,348
Ending balance, value at Jun. 30, 2025		1,172,583		$ 17,348	283,667	717,869	0	153,699
Beginning balance, shares at Mar. 31, 2025			36,537	17,348
Beginning balance, value at Mar. 31, 2025		1,162,108		$ 17,348	283,667	709,108	0	151,985
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	$ 26,498	24,475				18,761		5,714
Cash dividends paid to parent by MGE		(10,000)				(10,000)
Distributions to parent from noncontrolling interest		(4,000)						(4,000)
Ending balance, shares at Jun. 30, 2025			36,542	17,348
Ending balance, value at Jun. 30, 2025		$ 1,172,583		$ 17,348	$ 283,667	$ 717,869	$ 0	$ 153,699

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Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2025

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Significant Accounting Principles

Summary of Significant Accounting Policies – MGE Energy and MGE.

a.Basis of Presentation.

This report is a combined report of MGE Energy and MGE. References in this report to "MGE Energy" are to MGE Energy, Inc. and its subsidiaries. References in this report to "MGE" are to Madison Gas and Electric Company.

MGE Power Elm Road and MGE Power West Campus own electric generating assets and lease those assets to MGE. Both entities are variable interest entities (VIE) under applicable authoritative accounting guidance. MGE is considered the primary beneficiary of these entities as a result of contractual agreements. As a result, MGE has consolidated MGE Power Elm Road and MGE Power West Campus in its financial reports. See Footnote 3 of the Notes to the Consolidated Financial Statements under Item 8, Financial Statements and Supplementary Data, of MGE Energy's and MGE's 2024 Annual Report on Form 10-K (the 2024 Annual Report on Form 10-K).

The accompanying consolidated financial statements as of June 30, 2025, and during the three and six months ended June 30, 2025, as applicable, are unaudited but include all adjustments that MGE Energy and MGE management consider necessary for a fair statement of their respective financial statements. All adjustments are of a normal, recurring nature except as otherwise disclosed. The year-end consolidated balance sheet information was derived from the audited balance sheet appearing in the 2024 Annual Report on Form 10-K but does not include all disclosures required by accounting principles generally accepted in the United States of America. These notes should be read in conjunction with the financial statements and the notes thereto located on pages 53 through 99 of the 2024 Annual Report on Form 10-K.

b.Cash, Cash Equivalents, and Restricted Cash.

The following table presents the components of total cash, cash equivalents, and restricted cash on the consolidated balance sheets.

	MGE Energy				MGE
	June 30,		December 31,		June 30,		December 31,
(In thousands)	2025		2024		2025		2024
Cash and cash equivalents	$	10,569	$	21,302	$	3,525	$	16,865
Restricted cash		869		1,113		869		1,113
Receivable - margin account		1,698		2,081		1,698		2,081
Cash, cash equivalents, and restricted cash	$	13,136	$	24,496	$	6,092	$	20,059

Cash Equivalents

All highly liquid investments purchased with an original maturity of three months or less are considered to be cash equivalents.

Restricted Cash

MGE has certain cash accounts that are restricted to uses other than current operations and designated for a specific purpose. MGE's restricted cash accounts include cash held by trustees for certain employee benefits and cash deposits held by third parties. These are included in "Other current assets" on the consolidated balance sheets.

Receivable – Margin Account

Cash amounts held by counterparties as margin collateral for certain financial transactions are recorded as Receivable – margin account in "Other current assets" on the consolidated balance sheets. The costs being hedged are fuel for electric generation, purchased power, and cost of gas sold.

c.Property, Plant, and Equipment.

Columbia.

An asset that will be retired in the near future and substantially in advance of its previously expected retirement date is subject to abandonment accounting. In the second quarter of 2021, the operator of Columbia received approval from Midcontinent Independent System Operator (MISO) to retire Columbia Units 1 and 2. The co-owners intend to retire Unit 1 and Unit 2 by the end of 2029. Final timing and retirement dates continue to be evaluated and depend upon operational and regulatory considerations, capacity needs and availability, and other factors impacting one or more of the Columbia co-owners. As of June 30, 2025, early retirement of Columbia Unit 1 and 2 was probable.

Our ownership share of Columbia assets was classified as plant to be retired within "Property, plant, and equipment, net" on the consolidated balance sheets contained in the 2024 Annual Report on Form 10-K. Assets for Columbia Unit 1 and Unit 2 are currently included in rate base, and MGE continues to depreciate them on a straight-line basis using the composite depreciation rates approved by the Public Service Commission of Wisconsin (PSCW) that include retirement dates of 2029 for both Units.

If it becomes probable that regulators will disallow full recovery or a return on the remaining net book value of a generating unit that is either abandoned or probable of being abandoned, an impairment loss would be required. An impairment loss would be recorded to the extent that the remaining net book value of the generating unit exceeds the present value of the amount expected to be recovered from ratepayers. No impairment was recorded as of June 30, 2025.

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New Accounting Standards

6 Months Ended

Jun. 30, 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 is effective for annual disclosures for fiscal years beginning after December 15, 2024. MGE has adopted 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.

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 financial statements.

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Investment in ATC and ATC Holdco

6 Months Ended

Jun. 30, 2025

Equity Method Investments and Joint Ventures [Abstract]

Investment in ATC and ATC Holdco

Investment in ATC and ATC Holdco - MGE Energy and MGE.

ATC owns and operates electric transmission facilities primarily in Wisconsin. MGE received an interest in ATC when it, like other Wisconsin electric utilities, contributed its electric transmission facilities to ATC, as required by Wisconsin law. That interest is presently held by MGE Transco, a subsidiary of MGE Energy. ATC Holdco was formed by several members of ATC, including MGE Energy, to pursue electric transmission development and investments outside of Wisconsin. The ownership interest in ATC Holdco is held by MGEE Transco, a subsidiary of MGE Energy.

MGE Transco and MGEE Transco have accounted for their investments in ATC and ATC Holdco, respectively, under the equity method of accounting. Equity earnings from investments are recorded as "Other income" on the consolidated statements of income of MGE Energy. MGE Transco recorded the following amounts related to its investment in ATC:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In thousands)	2025		2024		2025		2024
Equity earnings from investment in ATC	$	3,066	$	2,748	$	6,056	$	5,470
Dividends received from ATC		2,345		2,132		5,632		4,238
Capital contributions to ATC		2,679		1,070		5,171		1,785

In July 2025, MGE Transco made a $3.2 million capital contribution to ATC.

ATC's summarized financial data is as follows:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
(In thousands)	2025			2024			2025			2024
Operating revenues	$	241,227		$	218,222		$	476,156		$	430,150
Operating expenses		(117,564	)		(109,197	)		(234,309	)		(214,039	)
Other income, net		550			356			633			543
Interest expense, net		(43,254	)		(36,040	)		(82,447	)		(71,458	)
Earnings before members' income taxes	$	80,959		$	73,341		$	160,033		$	145,196

MGE receives transmission and other related services from ATC. During the three and six months ended June 30, 2025, MGE recorded $10.2 million and $20.4 million, respectively, for transmission service compared to $9.1 million and $18.2 million for the comparable periods in 2024. MGE also provides a variety of operational, maintenance, and project management work for ATC, which is reimbursed by ATC. As of June 30, 2025 and December 31, 2024, MGE had a receivable due from ATC of $0.5 million and $2.0 million, respectively. The receivable is primarily related to transmission interconnection activities at the Paris and Darien solar generation sites. MGE will be reimbursed for these costs after the new generation assets are placed into service.

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Taxes

6 Months Ended

Jun. 30, 2025

Income Tax Disclosure [Abstract]

Taxes

Taxes - MGE Energy and MGE.

Effective Tax Rate.

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 June 30,	2025				2024				2025				2024
Statutory federal income tax rate		21.0		%		21.0		%		21.0		%		21.0		%
State income taxes, net of federal benefit		6.4				6.2				6.2				6.2
Amortized investment tax credits		(1.3	)			(2.4	)			(1.4	)			(2.6	)
Credit for electricity from renewable energy		(13.2	)			(11.7	)			(14.4	)			(12.9	)
AFUDC equity, net		(0.5	)			(0.7	)			(0.5	)			(0.7	)
Amortization of utility excess deferred tax - tax reform(a)		(2.5	)			(6.8	)			(2.7	)			(7.5	)
Other, net, individually insignificant		0.2				0.2				0.2				0.1
Effective income tax rate		10.1		%		5.8		%		8.4		%		3.6		%
	MGE Energy								MGE
Six Months Ended June 30,	2025				2024				2025				2024
Statutory federal income tax rate		21.0		%		21.0		%		21.0		%		21.0		%
State income taxes, net of federal benefit		6.3				6.2				6.2				6.2
Amortized investment tax credits		(1.3	)			(2.3	)			(1.5	)			(2.5	)
Credit for electricity from renewable energy		(11.0	)			(10.8	)			(11.9	)			(11.9	)
AFUDC equity, net		(0.6	)			(0.7	)			(0.6	)			(0.7	)
Amortization of utility excess deferred tax - tax reform(a)		(2.5	)			(6.4	)			(2.8	)			(7.0	)
Other, net, individually insignificant		0.1				(0.1	)			0.1				(0.2	)
Effective income tax rate		12.0		%		6.9		%		10.5		%		4.9		%

(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 June 30, 2025 and 2024, MGE recognized $0.9 million. For both the six months ended June 30, 2025 and 2024, MGE recognized $1.8 million. For the three and six months ended June 30, 2024, MGE recognized $1.0 million and $2.1 million, respectively, of deferred taxes not restricted by IRS normalization rules.

In 2024, MGE sold transfer-eligible tax credits generated in 2023 and 2024. MGE elects to account for the transferred tax credits under the framework of Accounting for Income Taxes. The sale of tax credits is presented in the operating activities section of the consolidated statements of cash flows consistent with the presentation of cash taxes paid. MGE includes any expected proceeds from the transfer of tax credits in the evaluation of realizability of deferred tax assets related to tax credits

and records a valuation allowance for the difference between the tax value of the credits and the expected proceeds. The PSCW approved the deferral by MGE of any differential between tax credit transfer proceeds and the tax value of credits reflected in rates to its next rate case filing.

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Pension and Other Postretirement Plans

6 Months Ended

Jun. 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						Six Months Ended
	June 30,						June 30,
(In thousands)	2025			2024			2025			2024
Pension Benefits
Components of net periodic benefit cost:
Service cost	$	655		$	780		$	1,306		$	1,539
Interest cost		4,313			4,315			8,569			8,559
Expected return on assets		(7,246	)		(7,148	)		(14,507	)		(14,299	)
Amortization of:
Actuarial loss		102			313			150			429
Net periodic benefit (credit) cost	$	(2,176	)	$	(1,740	)	$	(4,482	)	$	(3,772	)
Postretirement Benefits
Components of net periodic benefit cost:
Service cost	$	188		$	217		$	371		$	428
Interest cost		754			779			1,514			1,576
Expected return on assets		(634	)		(693	)		(1,358	)		(1,384	)
Amortization of:
Transition obligation		—			—			1			1
Prior service credit		—			(4	)		—			(8	)
Actuarial gain		(173	)		(129	)		(321	)		(206	)
Net periodic benefit cost	$	135		$	170		$	207		$	407

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. During the three and six months ended June 30, 2025, MGE recovered $0.1 million and $0.7 million, respectively, of pension and other postretirement costs previously deferred, compared to $1.2 million and $2.6 million for the same periods in 2024. These costs have not been reflected in the table above.

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Equity and Financing Arrangements

6 Months Ended

Jun. 30, 2025

Equity and Financing Arrangements Disclosure [Abstract]

Equity and Financing Arrangements

Equity and Financing Arrangements - MGE Energy.

a.Common Stock.

MGE Energy sells shares of its common stock through its Direct Stock Purchase and Dividend Reinvestment Plan (the Stock Plan). Those shares may be newly issued shares or shares that are purchased in the open market by an independent agent for participants in the Stock Plan. Effective May 2025, MGE Energy transitioned to utilizing open market purchases for all shares issued under the Stock Plan. Sales of newly issued shares under the Stock Plan are covered by a shelf registration statement that MGE Energy filed with the SEC. During the six months ended June 30, 2025, MGE Energy issued approximately 40,995 shares of common stock under the Stock Plan. The net proceeds from these issuances were approximately $3.8 million, which were used for general corporate purposes.

b.Dilutive Shares Calculation.

As of June 30, 2025, 30,803 shares were included in the calculation of diluted earnings per share related to nonvested equity awards. See Footnote 7 for additional information on share-based compensation awards.

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Share-Based Compensation

6 Months Ended

Jun. 30, 2025

Share-Based Payment Arrangement [Abstract]

Share-Based Compensation

Share-Based Compensation - MGE Energy and MGE.

During the three and six months ended June 30, 2025, MGE recorded $0.5 million and $1.7 million, respectively, in compensation expense related to share-based compensation awards compared to $0.7 million and $1.9 million, respectively, for the comparable periods in 2024.

In the first quarter of 2025, MGE distributed cash payments of $2.0 million and 11,213 shares of common stock related to awards that were granted in 2022 under the 2021 Incentive Plan.

In March 2025, MGE granted 18,136 performance units and 26,398 restricted stock units under the 2021 Incentive Plan to eligible employees and non-employee directors.

Share-based compensation expense is recognized on a straight-line basis over the requisite service period. Awards classified as equity awards are measured based on their grant-date fair value. Awards classified as liability awards are recorded at fair value each reporting period. The performance units can be paid out in cash, shares of common stock, or a combination of cash and stock and are classified as a liability award. The restricted stock units will be paid out in shares of common stock, and therefore are classified as equity awards.

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Commitments and Contingencies

6 Months Ended

Jun. 30, 2025

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Commitments and Contingencies - MGE Energy and MGE.

a.Environmental.

In February 2021, MGE and the other co-owners of Columbia announced plans to retire Units 1 and 2 at that facility. Effects of the environmental compliance requirements discussed below will depend upon the final Columbia retirement dates approved and required compliance dates of applicable regulations in effect.

MGE Energy and MGE are subject to frequently changing local, state, and federal regulations concerning air quality, water quality, land use, threatened and endangered species, hazardous materials handling, and solid waste disposal. These regulations affect the manner in which operations are conducted, the costs of operations, as well as capital and operating expenditures. Several of these environmental rules are subject to legal challenges, reconsideration and/or other uncertainties. Regulatory initiatives, proposed rules, and court challenges to adopted rules could potentially have a material effect on capital expenditures and operating costs. Management believes compliance costs will be recovered in future rates based on previous treatment of environmental compliance projects.

These initiatives, proposed rules, and court challenges include:

•The United States Environmental Protection Agency's (EPA) promulgated water Effluent Limitations Guidelines (ELG) and standards for steam electric power plants that focus on the reduction of metals and other pollutants in wastewater from new and existing power plants.

With the closure of the wet pond system in 2023 (as described in further detail in the CCR section below), Columbia complies with ELG requirements. With the installation of additional wastewater treatment equipment completed in 2023, the Elm Road Units comply with ELG requirements.

In May 2024, the EPA finalized the ELG rule that further regulates the wastewater discharges associated with coal-fired power plants. The rule focuses on wastewater discharges from flue gas desulfurization and bottom ash transport water. The rule includes a reduction in requirements for plants that have already installed pollution controls based on previous versions of the rule, and for plants that will be retiring or switching to natural gas by certain dates. Although the 2024 ELG rule is currently being challenged in federal court, the litigation is on hold while the EPA undertakes a reconsideration process. The 2024 rule builds upon the 2020 ELG Rule, which also remains under legal challenge and is similarly on hold pending the outcome of the EPA's review.

Pollution control prevention equipment was installed under previous versions of the rule and the planned fuel switching to natural gas. MGE and the operator of the Elm Road Units are currently evaluating operational options and costs for Elm Road to be in compliance with the requirements of the rule.

•The EPA's cooling water intake rule requires cooling water intake structures at electric power plants to meet best technology available (BTA) standards to reduce the mortality from entrainment (drawing aquatic life into a plant's cooling system) and impingement (trapping aquatic life on screens of cooling water intake structures).

Blount received its most recent Wisconsin Pollutant Discharge Elimination System (WPDES) permit from the Wisconsin Department of Natural Resources (WDNR) in October 2023. Blount's latest WPDES permit assumes that the plant meets BTA standards for entrainment for the duration of this permit which expires in 2028. The WDNR included a requirement to conduct an optimization study to demonstrate compliance with impingement BTA standards in the latest permit that needs to be completed by January 2028. Once the WDNR determines the impingement requirements at Blount, MGE will be able to determine any compliance costs of meeting Blount's permit requirements.

Intakes at Columbia are subject to this rule. The Columbia operator timely submitted its renewal application. BTA improvements required by the renewal permit will be coordinated with the owners' plan to retire both units by the end of 2029. MGE will continue to work with Columbia's operator to evaluate regulatory requirements in light of the planned retirement. MGE does not expect this rule to have a material effect on Columbia.

•Greenhouse Gas (GHG) new source performance standards and emission guidelines were established under the Clean Air Act for states to use in developing plans to control GHG emissions from fossil fuel-fired electric generating units, including existing and proposed regulations governing existing, new, or modified fossil-fuel generating units.

In May 2024, the EPA published its final performance standards and emission guidelines under Section 111(b) of the Clean Air Act for carbon dioxide emissions from new combustion turbines and existing fossil fuel-fired boilers used to produce electricity. The final rule granted some emissions flexibility for existing coal-fired units that retire and/or fuel switch by certain dates. For existing natural gas boiler units, the final rule established a process where states must submit plans to the EPA for establishing standards. States had two years from the publication date of these rules to submit plans to the EPA for review and approval. Preliminary evaluation of the final ruling showed that MGE met the requirements for the gas-fired boilers at Blount. Furthermore, MGE would meet the requirements for the coal-fired units at Columbia through planned unit retirements and the Elm Road Units through its transition to natural gas. In June 2025, the EPA published a proposed rule with two potential options: (1) repeal the performance standards and emission guidelines under Section 111 of the Clean Air Act associated with GHG emissions from fossil fuel-fired power plants, or (2) retain only the efficiency-based requirements for new natural gas-fired power plants and repeal all other aspects of the rule. In July 2025, EPA released a new proposed rule titled “Reconsideration of 2009 Endangerment Finding and Greenhouse Gas Vehicle Standards”. This proposal would repeal EPA’s 2009 GHG Endangerment Finding, which in effect, would undo the basis for federal regulation of GHG under the Clean Air Act. MGE will continue to follow these rule developments.

•The EPA's rule to regulate ambient levels of ozone through the 2015 Ozone National Ambient Air Quality Standards (NAAQS).

The Elm Road Units are located in Milwaukee County, Wisconsin, a serious nonattainment area for the 2015 Ozone NAAQS. At this time, the operator of the Elm Road Units does not expect that the 2015 Ozone NAAQS or the Milwaukee County nonattainment designation will have a direct material effect on the Elm Road Units.

•The EPA's rule to regulate Fine Particulate Matter (PM2.5).

In March 2024, the EPA published a final rule to lower the average annual PM2.5 NAAQS from 12 ug/m3 to 9 ug/m3 effective May 2024. The new annual PM2.5 NAAQS could impact Milwaukee County, where the Elm Road units are located, if the county is determined to be in nonattainment. A nonattainment designation would require the State of Wisconsin to develop a plan to get into attainment, which would likely include additional limitations for new and modified plants in the county. In February 2025, Wisconsin's Governor Evers submitted a state-wide attainment recommendation to the EPA.

The final impact of this rule will not be known until the EPA determines the attainment status of Wisconsin counties and the State of Wisconsin develops an attainment implementation plan for any areas not in attainment. MGE will continue to follow the rule's developments.

•Rules regulating nitrogen oxide (NOx) and sulfur dioxide (SO2) emissions, including the Good Neighbor Plan and Clean Air Visibility Rule.

The EPA's Good Neighbor Plan and its progeny are a suite of interstate air pollution transport rules designed to reduce ozone and PM2.5 ambient air levels in areas that the EPA has determined as being significantly impacted by pollution from upwind states. This is accomplished through a reduction in NOx and SO2 from qualifying fossil fuel-fired power plants and industrial boilers in upwind "contributing" states. NOx and SO2 contribute to fine particulate pollution and NOx contributes to ozone formation in downwind areas. Reductions are generally achieved through a cap-and-trade system. Individual plants can meet their caps through reducing emissions and/or buying allowances on the market.

In March 2023 (published June 2023), the EPA finalized its Federal Implementation Plan to address state obligations under the Clean Air Act "good neighbor" provisions for the 2015 Ozone NAAQS (Good Neighbor Plan). The Good Neighbor Plan impacts 23 states, including Wisconsin. For Wisconsin, the Good Neighbor Plan includes revisions to the current obligations for fossil-fuel power generation, which includes Blount, Columbia, the Elm Road Units, WCCF, West Riverside, and West Marinette. Emissions budgets can be met with planned retirements, fuel switching, and immediately available measures, including consistently operating emissions controls already installed at power plants. In 2026, additional obligations would go into effect, including a further reduction in emissions budgets. Wisconsin would need to submit a State Implementation Plan to meet its obligations or accept the EPA's Good Neighbor Plan.

Multiple legal challenges to the Good Neighbor Plan and related state implementation plan disapprovals are pending, including in the United States Court of Appeals for the District of Columbia. In June 2024, the Supreme Court of the United States granted a request to stay the Good Neighbor Plan and block its enforcement pending judicial review by the U.S. Court of Appeals for the District of Columbia on the merits of petitioner's challenges to implementation of the rule. The EPA has temporarily halted the enforcement of the Good Neighbor Plan's requirements for all pollution sources in states affected by the plan, including Wisconsin. While the EPA addresses these concerns, interim rules have been implemented in Wisconsin to address interstate pollution. Based on MGE's current evaluation, if the Good Neighbor Plan goes into effect as-is, the 2026 additional emission reductions may impact the Elm Road Units. However, final impact of the rules will not be known until judicial reviews are completed and/or the EPA takes further action regarding the rule.

•The EPA's Coal Combustion Residuals (CCR) Rule.

The CCR rule regulates the disposal of solid waste coal ash and defines what ash use activities would be considered generally exempt beneficial reuse of coal ash. The CCR rule also regulates landfills, ash ponds, and other surface impoundments used for coal combustion residuals by regulating their design, location, monitoring, and operation. The CCR rule requires owners and operators of coal-fired power plants to stop transporting CCR and non-CCR wastewater to unlined surface impoundments. At Columbia, the coal combustion residuals system completed in 2023 replaced the unlined surface impoundment, and Columbia complies with this rule.

Review of the Elm Road Units has indicated that the costs to comply with the CCR rule are not expected to be significant.

In May 2024, the EPA published its final CCR Legacy Rule. The CCR Legacy Rule applies to previously closed disposal sites. In 2024, MGE recorded an asset retirement obligation for its estimated share of the legal liability associated with the effect of the CCR Legacy Rule for remediation and groundwater compliance monitoring at Columbia. Actual costs of compliance may be different than the amount recorded due to potential changes in compliance strategies that will be used, as well as other potential changes in cost estimate.

b.Legal Matters.

MGE is involved in various legal matters that are being defended and handled in the normal course of business. MGE accrues for costs that are probable of being incurred and subject to reasonable estimation. The accrued amount for these matters is not material to the financial statements. MGE does not expect the resolution of these matters to have a material adverse effect on its consolidated results of operations, financial condition, or cash flows.

c.Purchase Contracts.

MGE Energy and MGE have entered into various commodity supply, transportation, and storage contracts to meet their obligations to deliver electricity and natural gas to customers. Management expects to recover these costs in future customer rates. The following table shows future commitments related to purchase contracts as of June 30, 2025:

(In thousands)	2025		2026		2027		2028		2029		Thereafter
Coal(a)	$	9,437	$	8,387	$	4,043	$	4,126	$	—	$	—
Natural gas(b)		26,109		51,334		37,306		41,131		40,951		316,598
Renewable energy(c)		6,084		3,454		3,324		3,324		1,350		38,100
	$	41,630	$	63,175	$	44,673	$	48,581	$	42,301	$	354,698

(a)Total coal commitments for MGE's share of the Columbia and Elm Road Units, including transportation. Fuel procurement for MGE's jointly owned Columbia and Elm Road Units is handled by Wisconsin Power and Light Company and WEPCO, respectively, who are the operators of those facilities.

(b)MGE's natural gas transportation and storage contracts require fixed monthly payments for firm supply pipeline transportation and storage capacity. The pricing components of the fixed monthly payments for the transportation and storage contracts are approved by FERC but may be subject to change. MGE's natural gas supply commitments include market-based pricing.

(c)Operational commitments for solar and wind facilities.

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Rate Matters

6 Months Ended

Jun. 30, 2025

Regulated Operations [Abstract]

Rate Matters

Rate Matters - MGE Energy and MGE.

a.Rate Proceedings.

	Rate increase	Return on Common Equity	Common Equity Component of Regulatory Capital Structure	Effective Date
Approved 2024/2025 rate proceeding(a)(b)
Electric	1.54%	9.7%	56.1%	1/1/2024
Gas	2.44%	9.7%	56.1%	1/1/2024
Electric(c)	2.63%	9.7%	56.1%	1/1/2025
Gas	1.32%	9.7%	56.1%	1/1/2025
Proposed 2026/2027 rate proceeding(d)
Electric(e)	4.89%	10.0%	56.1%	1/1/2026
Gas(e)	2.33%	10.0%	56.1%	1/1/2026
Electric(f)	4.33%	10.0%	56.0%	1/1/2027
Gas(f)	2.16%	10.0%	56.0%	1/1/2027

(a)The electric rate increase was driven by an increase in rate base including our investments made in West Riverside, local solar, continued investment in grid modernization, as well as higher costs for transmission, pension and other post retirement benefits, and uncollectible costs (including costs previously deferred from prior years). This increase in electric costs is offset by a decrease in fuel costs and benefit from lower tax expense (including impacts from the Inflation Reduction Act). MGE filed an updated 2025 fuel forecast with the PSCW in 2024, which will impact rates in 2025, based on any variance between the forecast submitted as part of the rates and updated forecast. In addition, the PSCW authorized MGE to defer a recovery of and a return on costs associated for any change in the in-service date for Paris and force majeure costs for Badger Hollow II and Paris that were not reflected in this rate filing. The PSCW also approved deferral of any differential in PTC tax credits reflected in rates and actual credits produced. These deferrals will be reflected in MGE's next rate case filing. The gas rate increases were also driven by our investment made in grid modernization and higher pension and other post retirement benefits and uncollectible costs (including costs previously deferred from prior years). This increase in gas costs is offset by a tax benefit related to excess deferred taxes. Included in the gas residential rate is a reduction in the customer fixed charge.

(b)The 2024/2025 rate order includes an earnings sharing mechanism, under which, if MGE earns above the authorized Return on Equity (ROE) in the rate order: (i) the utility will retain 100.0% of earnings for the first 15 basis points above the authorized ROE; (ii) 50.0% of the next 60 basis points will be required to be deferred and returned to customers; and (iii) 100.0% of any remaining excess earnings will be required to be refunded to customers. The earnings calculation excludes fuel rules adjustments. See "Fuel Rules" below.

(c)The PSCW approved a 2025 Fuel Cost Plan in December 2024. The plan lowered the 2025 increase in electric rates to 2.63% to reflect lower expected fuel costs.

(d)In April 2025, MGE filed a proposed 2-year rate case and PSCW approval is pending. A final order is expected before the end of the year.

(e)The proposed electric rate increase reflects growth in rate base, primarily from investments in Paris (battery), Darien (battery), Sunnyside (solar), West Riverside, and continued investment in grid modernization, as well as higher costs for transmission. The increase in electric costs is offset by a decrease in fuel costs, changes in pension and other post retirement benefits, and benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas increase is driven by an increase in rate base including continued distribution infrastructure improvements designed to enhance reliability and safety and system modernization. The increase in gas costs is offset by changes in pension and other post retirement benefits.

(f)The proposed electric rate increase is driven by an increase in rate base including investments made in the Koshkonong (solar), Sunnyside (battery), and High Noon (solar/battery) projects, and continued investment in grid modernization projects. The increase in electric costs is offset by a benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas rate increase is driven by an increase in rate base.

b.Fuel Rules.

Fuel rules require Wisconsin utilities to defer electric fuel-related costs that fall outside a symmetrical cost tolerance band around the amount approved for a utility in its annual fuel proceedings. Any over- or under-recovery of the actual costs is determined in the following year and is then reflected in future billings to electric retail customers. The fuel rules bandwidth is set at plus or minus 2% in 2025 and 2024. The electric fuel-related costs are subject to an excess revenues test. Excess revenues are defined as revenues in the year in question that provide MGE with a greater return on common equity than authorized by the PSCW in MGE's latest rate order. The recovery of under-collected electric fuel-related costs would be reduced by the amount that exceeds the excess revenue test. These costs are subject to the PSCW's annual review of fuel costs completed in the year following the deferral. The following table summarizes deferred electric fuel-related costs:

	Fuel Costs (Savings) (in millions)	Refund or Recovery Period
2022	$8.8(a)	October 2023 through September 2024
2023	($7.2)(a)	October 2024 through December 2024
2024	($3.0)(a)	October 2025
2025	($2.5)	(b)

(a)There was no change to the refund or recovery in the fuel rules proceedings from the amount MGE deferred.

(b)These costs will be subject to the PSCW's annual review of 2025 fuel costs, expected to be completed in 2026.

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Derivative and Hedging Instruments

6 Months Ended

Jun. 30, 2025

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative and Hedging Instruments

Derivative and Hedging Instruments - MGE Energy and MGE.

a.Purpose.

As part of its regular operations, MGE enters into contracts, including options, swaps, futures, forwards, and other contractual commitments, to manage its exposure to commodity prices. To the extent that these contracts are derivatives, MGE assesses whether or not the normal purchases or normal sales exclusion applies. For contracts to which this exclusion cannot be applied, the derivatives are recognized in the consolidated balance sheets at fair value. MGE's financial commodity derivative activities are conducted in accordance with its electric and gas risk management program, which is approved by the PSCW and limits the volume MGE can hedge with specific risk management strategies. The maximum length of time over which cash flows related to energy commodities can be hedged is four years. If the derivative qualifies for regulatory deferral, the derivatives are marked to fair value and are offset with a corresponding regulatory asset or liability depending on whether the derivative is in a net loss or net gain position, respectively. The deferred gain or loss is recognized in earnings in the delivery month applicable to the instrument. Gains and losses related to hedges qualifying for regulatory treatment are refundable or recoverable in gas rates through the Purchased Gas Adjustment (PGA) or in electric rates as a component of the fuel rules mechanism.

b.Notional Amounts.

The gross notional volume of open derivatives is as follows:

	June 30, 2025			December 31, 2024
Commodity derivative contracts		279,520	MWh		307,640	MWh
Commodity derivative contracts		6,662,500	Dth		6,285,000	Dth
FTRs		5,159	MW		2,131	MW

c.Financial Statement Presentation.

MGE purchases and sells exchange-traded and over-the-counter options, swaps, and future contracts. These arrangements are primarily entered into to help stabilize the price risk associated with gas or power purchases. These

transactions are employed by both MGE's gas and electric segments. Additionally, as a result of the firm transmission agreements that MGE holds on electricity transmission paths in the MISO market, MGE holds financial transmission rights (FTRs). An FTR is a financial instrument that entitles the holder to a stream of revenues or charges based on the differences in hourly day-ahead energy prices between two points on the transmission grid. The fair values of these instruments are offset with a corresponding regulatory asset/liability depending on whether the instruments are in a net loss/gain position. Depending on the nature of the instrument, the gain or loss associated with these transactions will be reflected as cost of gas sold, fuel for electric generation, or purchased power expense in the delivery month applicable to the instrument. As of June 30, 2025, and December 31, 2024, the fair value of exchange traded derivatives and FTRs exceeded their cost basis by $0.7 million and $0.1 million, respectively.

The following table summarizes the fair value of the derivative instruments on the consolidated balance sheets. All derivative instruments in this table are presented on a gross basis and are calculated prior to the netting of instruments with the same counterparty under a master netting agreement as well as the netting of collateral. For financial statement purposes, instruments are netted with the same counterparty under a master netting agreement as well as the netting of collateral.

	Derivative		Derivative
(In thousands)	Assets		Liabilities		Balance Sheet Location
June 30, 2025
Commodity derivative contracts(a)	$	1,455	$	1,192	Other current assets
Commodity derivative contracts(a)		223		47	Other deferred charges
FTRs		258		—	Other current assets
December 31, 2024
Commodity derivative contracts(a)	$	927	$	1,121	Other current liabilities
Commodity derivative contracts(a)		286		140	Other deferred liabilities and other
FTRs		108		—	Other current assets

(a)As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

The following table shows the effect of netting arrangements for recognized derivative assets and liabilities that are subject to a master netting arrangement or similar arrangement on the consolidated balance sheets.

Offsetting of Derivative Assets and Liabilities

(In thousands)	Gross Amounts		Gross Amounts Offset in Balance Sheets			Collateral Posted Against Derivative Positions			Net Amount Presented in Balance Sheets
June 30, 2025
Assets
Commodity derivative contracts	$	1,678	$	(1,239	)	$	—		$	439
FTRs		258		—			—			258
Liabilities
Commodity derivative contracts		1,239		(1,239	)		—			—
December 31, 2024
Assets
Commodity derivative contracts	$	1,213	$	(1,213	)	$	—		$	—
FTRs		108		—			—			108
Liabilities
Commodity derivative contracts		1,261		(1,213	)		(48	)		—

The following tables summarize the unrealized and realized gains/losses related to the derivative instruments on the consolidated balance sheets and the consolidated statements of income.

	2025						2024
(In thousands)	Current and Long-Term Regulatory Asset (Liability)			Other Current Assets			Current and Long-Term Regulatory Asset (Liability)			Other Current Assets
Three Months Ended June 30:
Balance as of April 1,	$	(1,860	)	$	78		$	3,009		$	275
Unrealized loss		2,118			—			758			—
Realized (loss) gain reclassified to a deferred account		(288	)		288			(537	)		537
Realized (loss) gain reclassified to income statement		(667	)		30			(1,284	)		(285	)
Balance as of June 30,	$	(697	)	$	396		$	1,946		$	527
Six Months Ended June 30:
Balance as of January 1,	$	(60	)	$	388		$	5,226		$	1,569
Unrealized loss		362			—			2,898			—
Realized (loss) gain reclassified to a deferred account		263			(263	)		(2,694	)		2,694
Realized (loss) gain reclassified to income statement		(1,262	)		271			(3,484	)		(3,736	)
Balance as of June 30,	$	(697	)	$	396		$	1,946		$	527

	Realized Losses (Gains)
	2025					2024
(In thousands)	Fuel for Electric Generation/ Purchased Power		Cost of Gas Sold			Fuel for Electric Generation/ Purchased Power		Cost of Gas Sold
Three Months Ended June 30:
Commodity derivative contracts	$	198	$	—		$	1,328	$	—
FTRs		439		—			241		—
Six Months Ended June 30:
Commodity derivative contracts	$	596	$	(203	)	$	3,754	$	3,265
FTRs		598		—			201		—

MGE's commodity derivative contracts and FTRs are subject to regulatory deferral. These derivatives are marked to fair value and are offset with a corresponding regulatory asset or liability. Realized gains and losses are deferred on the consolidated balance sheets and are recognized in earnings in the delivery month applicable to the instrument. As a result of the treatment described above, there are no unrealized gains or losses that flow through earnings.

Certain counterparties extend MGE a credit limit. If MGE exceeds these limits, the counterparties may require collateral to be posted. As of June 30, 2025, and December 31, 2024, no counterparties were in a net liability position.

Nonperformance of counterparties to the non-exchange traded derivatives could expose MGE to credit loss. However, MGE enters into transactions only with companies that meet or exceed strict credit guidelines, and it monitors these counterparties on an ongoing basis to mitigate nonperformance risk in its portfolio. As of June 30, 2025, no counterparties had defaulted.

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Fair Value of Financial Instruments

6 Months Ended

Jun. 30, 2025

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

Fair Value of Financial Instruments - MGE Energy and MGE.

Fair value is defined as the price that would be received to sell an asset or would be paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. The accounting standard clarifies that fair value should be based on the assumptions market participants would use when pricing the asset or liability including assumptions about risk. The standard also establishes a

three-level fair value hierarchy based upon the observability of the assumptions used and requires the use of observable market data when available. The levels are:

Level 1 - Pricing inputs are quoted prices within active markets for identical assets or liabilities.

Level 2 - Pricing inputs are quoted prices within active markets for similar assets or liabilities; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations that are correlated with or otherwise verifiable by observable market data.

Level 3 - Pricing inputs are unobservable and reflect management's best estimate of what market participants would use in pricing the asset or liability.

a.Fair Value of Financial Assets and Liabilities Recorded at the Carrying Amount.

The carrying amount of cash, cash equivalents, and outstanding commercial paper approximates fair market value due to the short maturity of those investments and obligations. The estimated fair market value of long-term debt is based on quoted market prices for similar financial instruments. Since long-term debt is not traded in an active market, it is classified as Level 2. The estimated fair market value of financial instruments are as follows:

	June 30, 2025				December 31, 2024
(In thousands)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt(a)	$	770,775	$	710,479	$	773,400	$	698,765

(a)Includes long-term debt due within one year. Excludes debt issuance costs and unamortized discount of $4.1 million and $4.4 million as of June 30, 2025, and December 31, 2024, respectively.

b.Recurring Fair Value Measurements.

The following table presents the balances of assets and liabilities measured at fair value on a recurring basis for both MGE and MGE Energy.

	Fair Value as of June 30, 2025
(In thousands)	Total		Level 1		Level 2		Level 3
Assets:
Derivatives, net(b)	$	1,936	$	1,416	$	—	$	520
Liabilities:
Derivatives, net(b)	$	1,239	$	916	$	—	$	323
Deferred compensation		6,753		—		6,753		—
Total Liabilities	$	7,992	$	916	$	6,753	$	323

	Fair Value as of December 31, 2024
(In thousands)	Total		Level 1		Level 2		Level 3
Assets:
Derivatives, net(b)	$	1,321	$	987	$	—	$	334
Liabilities:
Derivatives, net(b)	$	1,261	$	480	$	—	$	781
Deferred compensation		6,468		—		6,468		—
Total Liabilities	$	7,729	$	480	$	6,468	$	781

(b)As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

Exchange-traded Investments. Investments include exchange-traded investment securities valued using quoted prices on active exchanges and are therefore classified as Level 1.

Deferred Compensation. The deferred compensation plans allow participants to defer certain cash compensation into notional investment accounts. These amounts are included within "Other deferred liabilities and other" in the consolidated balance sheets. The value of certain deferred compensation obligations is based on the market value of the

participants' notional investment accounts. The underlying notional investments are comprised primarily of equities, mutual funds, and fixed income securities that are based on directly and indirectly observable market prices. Since the deferred compensation obligations themselves are not exchanged in an active market, they are classified as Level 2.

The value of legacy deferred compensation obligations is based on notional investments that earn interest based upon the semiannual rate of U.S. Treasury Bills having a 26-week maturity increased by 1% compounded monthly with a minimum annual rate of 7%, compounded monthly. The notional investments are based upon observable market data, however, since the deferred compensation obligations themselves are not exchanged in an active market, they are classified as Level 2.

Derivatives. Derivatives include exchange-traded derivative contracts, over-the-counter transactions, and FTRs. Most exchange-traded derivative contracts are valued based on unadjusted quoted prices in active markets and are therefore classified as Level 1. A small number of exchange-traded derivative contracts are valued using quoted market pricing in markets with insufficient volumes and are therefore considered unobservable and classified as Level 3. Transactions done with an over-the-counter party are on inactive markets and are therefore classified as Level 3. These transactions are valued based on quoted prices from markets with similar exchange-traded transactions. FTRs are priced based upon monthly auction results for identical or similar instruments in a closed market with limited data available and are therefore classified as Level 3.

The following table summarizes the changes in Level 3 commodity derivative assets and liabilities measured at fair value on a recurring basis.

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In thousands)	2025		2024		2025		2024
Beginning balance	$	515	$	(1,726)	$	(447)	$	(2,604)
Realized and unrealized gains (losses):
Included in regulatory assets		—		294		—		1,172
Included in regulatory liability		(318)		—		642		—
Included in earnings		(665)		(1,330)		(1,262)		(3,855)
Settlements		665		1,330		1,264		3,855
Balance as of June 30,	$	197	$	(1,432)	$	197	$	(1,432)

The following table presents total realized and unrealized gains (losses) included in income for Level 3 assets and liabilities measured at fair value on a recurring basis(c).

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In thousands)	2025		2024		2025		2024
Purchased power expense	$	(665)	$	(1,330)	$	(1,262)	$	(3,855)

(c)MGE's exchange-traded derivative contracts, over-the-counter party transactions, purchased power agreement, and FTRs are subject to regulatory deferral. These derivatives are therefore marked to fair value and are offset in the financial statements with a corresponding regulatory asset or liability.

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Joint Plant Ownership

6 Months Ended

Jun. 30, 2025

Public Utilities, Property, Plant and Equipment [Abstract]

Jointly Owned Electric Utility Plant

Joint Plant Construction Project Ownership - MGE Energy and MGE

MGE has ownership interests in generation projects with other co-owners, some of which are under construction, as shown in the following table. Incurred costs are reflected in "Property, plant, and equipment, net" or "Construction work in progress" on the consolidated balance sheets.

Project	Ownership Interest	Source	Share of Generation	Share of Estimated Costs(a)	Costs incurred as of June 30, 2025(a)	Date of Commercial Operation
Paris(b)	10%	Battery	11 MW	$25 million(g)	$23.4 million	June 2025 Battery
Darien(c)	10%	Solar/Battery	25 MW/7.5 MW	$63 million(g)	$46.3 million	March 2025 Solar 2026 Battery(h)
Koshkonong(d)	10%	Solar/Battery	30 MW/16.5 MW	$104 million(g)	$24.8 million	2026 Solar(h) 2027 Battery(h)
High Noon(e)	10%	Solar/Battery	30 MW/16.5 MW	$99 million	$17.8 million	2027(h)
Columbia Energy Dome(f)	19%	Storage	3 MW	$17 million	$0.7 million	2027(h)

(a)Excluding AFUDC.

(b)Paris Solar-Battery Park is located in the Town of Paris in Kenosha County, Wisconsin.

(c)Darien Solar Energy Center is located in Walworth and Rock Counties in southern Wisconsin.

(d)Koshkonong Solar Energy Center is located in the Towns of Christiana and Deerfield in Dane County, Wisconsin.

(e)High Noon Solar Project is located in Columbia County, Wisconsin.

(f)Columbia Energy Dome is located in Columbia County, Wisconsin.

(g)Estimated costs are expected to exceed PSCW previously approved Certificate of Authority (CA) levels. Notifications are provided to the PSCW when costs increase above CA levels. MGE has and will continue to request recovery of the updates in its rate case proceedings.

(h)Estimated date of commercial operation.

MGE received specific approval to recover 100% AFUDC on Paris, Darien, Koshkonong, High Noon, and Columbia Energy Dome. During the three and six months ended June 30, 2025, MGE recognized $0.5 million and $2.1 million, respectively, after tax, in AFUDC for these projects compared to $1.5 million and $2.7 million, respectively, after tax, for the comparable periods in 2024.

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Revenue

6 Months Ended

Jun. 30, 2025

Revenue from Contract with Customer [Abstract]

Revenue from Contract with Customer

Revenue - MGE Energy and MGE.

Revenues disaggregated by revenue source were as follows:

	Three Months Ended				Six Months Ended
(In thousands)	June 30,				June 30,
Electric revenues	2025		2024		2025		2024
Residential	$	43,182	$	40,321	$	88,321	$	81,462
Commercial		64,027		64,161		124,662		124,024
Industrial		3,117		3,445		6,081		6,855
Other-retail/municipal		10,342		10,403		19,690		20,093
Total retail		120,668		118,330		238,754		232,434
Sales to the market		7,840		1,519		14,320		2,595
Other		805		534		1,693		1,479
Total electric revenues		129,313		120,383		254,767		236,508
Gas revenues
Residential		17,956		15,589		71,824		58,987
Commercial/Industrial		10,434		7,876		47,547		37,400
Total retail		28,390		23,465		119,371		96,387
Gas transportation		1,384		1,505		3,697		3,585
Other		151		146		338		313
Total gas revenues		29,925		25,116		123,406		100,285
Non-regulated energy revenues		214		214		249		256
Total Operating Revenue	$	159,452	$	145,713	$	378,422	$	337,049

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Segment Information

6 Months Ended

Jun. 30, 2025

Segment Reporting [Abstract]

Segment Information

Segment Information - MGE Energy and MGE

MGE Energy operates in the following business segments: electric utility, gas utility, nonregulated energy, transmission investment, and all other. See Footnote 22 to the consolidated financial statements included in Part II, Item 8 of the 2024 Annual Report on Form 10-K for additional discussion of each of these segments.

Fuel and purchased power and Purchased gas costs are significant segment expenses as defined in Segment Reporting. The Chief Operating Decision Maker does not review disaggregated assets on a segment basis; therefore, such information is not presented.

The following table shows segment information for MGE Energy's and MGE's operations:

(In thousands) MGE Energy	Electric			Gas			Non-Regulated Energy			Transmission Investment			Total Reportable Segments			All Others			Consolidation/ Elimination			Consolidated Total
Three Months Ended June 30, 2025
Operating revenues	$	129,313		$	29,925		$	214		$	—		$	159,452		$	—		$	—		$	159,452
Interdepartmental revenues		(28	)		2,558			11,121			—			13,651			—			(13,651	)		—
Total operating revenues		129,285			32,483			11,335			—			173,103			—			(13,651	)		159,452
Fuel and purchased power		(22,524	)		—			—			—			(22,524	)		—			670			(21,854	)
Purchased gas costs		—			(13,211	)		—			—			(13,211	)		—			1,898			(11,313	)
Depreciation and amortization		(22,094	)		(4,347	)		(1,913	)		—			(28,354	)		—			—			(28,354	)
Interest expense		(6,485	)		(1,768	)		(889	)		—			(9,142	)		—			—			(9,142	)
Other segment items(a)		(58,130	)		(15,015	)		(23	)		—			(73,168	)		(291	)		11,083			(62,376	)
Income tax (provision) benefit		(472	)		561			(2,318	)		(835	)		(3,064	)		89			—			(2,975	)
Equity in earnings of investments		—			—			—			3,060			3,060			—			—			3,060
Net income (loss)		19,580			(1,297	)		6,192			2,225			26,700			(202	)		—			26,498
Three Months Ended June 30, 2024
Operating revenues	$	120,383		$	25,116		$	214		$	—		$	145,713		$	—		$	—		$	145,713
Interdepartmental revenues		(55	)		2,172			10,946			—			13,063			—			(13,063	)		—
Total operating revenues		120,328			27,288			11,160			—			158,776			—			(13,063	)		145,713
Fuel and purchased power		(20,840	)		—			—			—			(20,840	)		—			753			(20,087	)
Purchased gas costs		—			(7,720	)		—			—			(7,720	)		—			1,427			(6,293	)
Depreciation and amortization		(20,888	)		(4,163	)		(1,881	)		—			(26,932	)		—			—			(26,932	)
Interest expense		(6,323	)		(1,709	)		(957	)		—			(8,989	)		—			—			(8,989	)
Other segment items(a)		(57,257	)		(14,456	)		(17	)		—			(71,730	)		(79	)		10,883			(60,926	)
Income tax (provision) benefit		641			810			(2,262	)		(758	)		(1,569	)		97			—			(1,472	)
Equity in earnings of investments		—			—			—			2,780			2,780			—			—			2,780
Net income		15,661			50			6,043			2,022			23,776			18			—			23,794
Six Months Ended June 30, 2025
Operating revenues	$	254,767		$	123,406		$	249		$	—		$	378,422		$	—		$	—		$	378,422
Interdepartmental revenues		(76	)		9,030			22,225			—			31,179			—			(31,179	)		—
Total operating revenues		254,691			132,436			22,474			—			409,601			—			(31,179	)		378,422
Fuel and purchased power		(45,630	)		—			—			—			(45,630	)		—			1,829			(43,801	)
Purchased gas costs		—			(72,501	)		—			—			(72,501	)		—			7,224			(65,277	)
Depreciation and amortization		(43,629	)		(8,579	)		(3,824	)		—			(56,032	)		—			—			(56,032	)
Interest expense		(12,978	)		(3,531	)		(1,795	)		—			(18,304	)		—			—			(18,304	)
Other segment items(a)		(114,109	)		(31,111	)		(67	)		—			(145,287	)		(727	)		22,126			(123,888	)
Income tax (provision) benefit		1,430			(4,426	)		(4,573	)		(1,702	)		(9,271	)		—			—			(9,271	)
Equity in earnings of investments		—			—			—			6,241			6,241			—			—			6,241
Net income (loss)		39,775			12,288			12,215			4,539			68,817			(727	)		—			68,090
Six Months Ended June 30, 2024
Operating revenues	$	236,508		$	100,285		$	256		$	—		$	337,049		$	—		$	—		$	337,049
Interdepartmental revenues		(109	)		7,383			21,773			—			29,047			—			(29,047	)		—
Total operating revenues		236,399			107,668			22,029			—			366,096			—			(29,047	)		337,049
Fuel and purchased power		(43,910	)		—			—			—			(43,910	)		—			1,677			(42,233	)
Purchased gas costs		—			(53,893	)		—			—			(53,893	)		—			5,723			(48,170	)
Depreciation and amortization		(41,538	)		(8,245	)		(3,749	)		—			(53,532	)		—			—			(53,532	)
Interest expense		(12,651	)		(3,419	)		(1,931	)		—			(18,001	)		—			—			(18,001	)
Other segment items(a)		(110,802	)		(29,161	)		(41	)		(2	)		(140,006	)		(392	)		21,647			(118,751	)
Income tax (provision) benefit		3,926			(2,286	)		(4,442	)		(1,506	)		(4,308	)		28			—			(4,280	)
Equity in earnings of investments		—			—			—			5,526			5,526			—			—			5,526
Net income (loss)		31,424			10,664			11,866			4,018			57,972			(364	)		—			57,608

(a)Other segment items include AFUDC Income, Other Income, Net, Other Operations and Maintenance, Other General Taxes, and Interest Revenue.

(In thousands) MGE	Electric			Gas			Non-Regulated Energy			Total Reportable Segments			Consolidation/ Elimination			Consolidated Total
Three Months Ended June 30, 2025
Operating revenues	$	129,313		$	29,925		$	214		$	159,452		$	—		$	159,452
Interdepartmental revenues		(28	)		2,558			11,121			13,651			(13,651	)		—
Total operating revenues		129,285			32,483			11,335			173,103			(13,651	)		159,452
Fuel and purchased power		(22,524	)		—			—			(22,524	)		670			(21,854	)
Purchased gas costs		—			(13,211	)		—			(13,211	)		1,898			(11,313	)
Depreciation and amortization		(22,094	)		(4,347	)		(1,913	)		(28,354	)		—			(28,354	)
Interest expense		(6,485	)		(1,768	)		(889	)		(9,142	)		—			(9,142	)
Other segment items(a)		(58,130	)		(15,015	)		(23	)		(73,168	)		11,083			(62,085	)
Income tax benefit (provision)		(472	)		561			(2,318	)		(2,229	)		—			(2,229	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(5,714	)		(5,714	)
Net income attributable to MGE		19,580			(1,297	)		6,192			24,475			(5,714	)		18,761
Three Months Ended June 30, 2024
Operating revenues	$	120,383		$	25,116		$	214		$	145,713		$	—		$	145,713
Interdepartmental revenues		(55	)		2,172			10,946			13,063			(13,063	)		—
Total operating revenues		120,328			27,288			11,160			158,776			(13,063	)		145,713
Fuel and purchased power		(20,840	)		—			—			(20,840	)		753			(20,087	)
Purchased gas costs		—			(7,720	)		—			(7,720	)		1,427			(6,293	)
Depreciation and amortization		(20,888	)		(4,163	)		(1,881	)		(26,932	)		—			(26,932	)
Interest expense		(6,323	)		(1,709	)		(957	)		(8,989	)		—			(8,989	)
Other segment items(a)		(57,257	)		(14,456	)		(17	)		(71,730	)		10,883			(60,847	)
Income tax benefit (provision)		641			810			(2,262	)		(811	)		—			(811	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(5,766	)		(5,766	)
Net income attributable to MGE		15,661			50			6,043			21,754			(5,766	)		15,988
Six Months Ended June 30, 2025
Operating revenues	$	254,767		$	123,406		$	249		$	378,422		$	—		$	378,422
Interdepartmental revenues		(76	)		9,030			22,225			31,179			(31,179	)		—
Total operating revenues		254,691			132,436			22,474			409,601			(31,179	)		378,422
Fuel and purchased power		(45,630	)		—			—			(45,630	)		1,829			(43,801	)
Purchased gas costs		—			(72,501	)		—			(72,501	)		7,224			(65,277	)
Depreciation and amortization		(43,629	)		(8,579	)		(3,824	)		(56,032	)		—			(56,032	)
Interest expense		(12,978	)		(3,531	)		(1,795	)		(18,304	)		—			(18,304	)
Other segment items(a)		(114,109	)		(31,111	)		(67	)		(145,287	)		22,126			(123,161	)
Income tax benefit (provision)		1,430			(4,426	)		(4,573	)		(7,569	)		—			(7,569	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(11,313	)		(11,313	)
Net income attributable to MGE		39,775			12,288			12,215			64,278			(11,313	)		52,965
Six Months Ended June 30, 2024
Operating revenues	$	236,508		$	100,285		$	256		$	337,049		$	—		$	337,049
Interdepartmental revenues		(109	)		7,383			21,773			29,047			(29,047	)		—
Total operating revenues		236,399			107,668			22,029			366,096			(29,047	)		337,049
Fuel and purchased power		(43,910	)		—			—			(43,910	)		1,677			(42,233	)
Purchased gas costs		—			(53,893	)		—			(53,893	)		5,723			(48,170	)
Depreciation and amortization		(41,538	)		(8,245	)		(3,749	)		(53,532	)		—			(53,532	)
Interest expense		(12,651	)		(3,419	)		(1,931	)		(18,001	)		—			(18,001	)
Other segment items(a)		(110,802	)		(29,161	)		(41	)		(140,004	)		21,647			(118,357	)
Income tax benefit (provision)		3,926			(2,286	)		(4,442	)		(2,802	)		—			(2,802	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(11,363	)		(11,363	)
Net income attributable to MGE		31,424			10,664			11,866			53,954			(11,363	)		42,591

(a)Other segment items include AFUDC Income, Other Income, Net, Other Operations and Maintenance, Other General Taxes, and Interest Revenue.

The following table shows segment information for MGE Energy's and MGE's capital expenditures:

	Utility				Consolidated
(In thousands) MGE Energy	Electric		Gas		Non-regulated Energy		Transmission Investment		All Others		Consolidation/ Elimination Entries		Total
Six Months Ended June 30, 2025	$	83,034	$	22,975	$	5,744	$	—	$	—	$	—	$	111,753
Six Months Ended June 30, 2024		86,755		20,879		3,988		—		—		—		111,622

	Utility				Consolidated
(In thousands) MGE	Electric		Gas		Non-regulated Energy		Consolidation/ Elimination Entries		Total
Six Months Ended June 30, 2025	$	83,034	$	22,975	$	5,744	$	—	$	111,753
Six Months Ended June 30, 2024		86,755		20,879		3,988		—		111,622

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Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Pay vs Performance Disclosure
Net Income (Loss)	$ 26,498	$ 23,794	$ 68,090	$ 57,608

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Insider Trading Arrangements	6 Months Ended
	Jun. 30, 2025
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

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Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2025

Accounting Policies [Abstract]

Variable Interest Entities

MGE Power Elm Road and MGE Power West Campus own electric generating assets and lease those assets to MGE. Both entities are variable interest entities (VIE) under applicable authoritative accounting guidance. MGE is considered the primary beneficiary of these entities as a result of contractual agreements. As a result, MGE has consolidated MGE Power Elm Road and MGE Power West Campus in its financial reports.

Cash and Cash Equivalents

Cash Equivalents

All highly liquid investments purchased with an original maturity of three months or less are considered to be cash equivalents.

Restricted Cash

Restricted Cash

MGE has certain cash accounts that are restricted to uses other than current operations and designated for a specific purpose. MGE's restricted cash accounts include cash held by trustees for certain employee benefits and cash deposits held by third parties. These are included in "Other current assets" on the consolidated balance sheets.

Receivable Margin Account

Receivable – Margin Account

Cash amounts held by counterparties as margin collateral for certain financial transactions are recorded as Receivable – margin account in "Other current assets" on the consolidated balance sheets. The costs being hedged are fuel for electric generation, purchased power, and cost of gas sold.

New Accounting Pronouncement Disclosure

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 is effective for annual disclosures for fiscal years beginning after December 15, 2024. MGE has adopted 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.

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 financial statements.

Investments - ATC and ATC Holdco

MGE Transco and MGEE Transco have accounted for their investments in ATC and ATC Holdco, respectively, under the equity method of accounting.

Pension and Other Postretirement Benefit Plan Assets

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.

Common Stock

MGE Energy sells shares of its common stock through its Direct Stock Purchase and Dividend Reinvestment Plan (the Stock Plan). Those shares may be newly issued shares or shares that are purchased in the open market by an independent agent for participants in the Stock Plan. Effective May 2025, MGE Energy transitioned to utilizing open market purchases for all shares issued under the Stock Plan. Sales of newly issued shares under the Stock Plan are covered by a shelf registration statement that MGE Energy filed with the SEC.

Wisconsin Fuel Rules

Fuel rules require Wisconsin utilities to defer electric fuel-related costs that fall outside a symmetrical cost tolerance band around the amount approved for a utility in its annual fuel proceedings. Any over- or under-recovery of the actual costs is determined in the following year and is then reflected in future billings to electric retail customers. The fuel rules bandwidth is set at plus or minus 2% in 2025 and 2024. The electric fuel-related costs are subject to an excess revenues test. Excess revenues are defined as revenues in the year in question that provide MGE with a greater return on common equity than authorized by the PSCW in MGE's latest rate order. The recovery of under-collected electric fuel-related costs would be reduced by the amount that exceeds the excess revenue test. These costs are subject to the PSCW's annual review of fuel costs completed in the year following the deferral.

Derivative Hedging

As part of its regular operations, MGE enters into contracts, including options, swaps, futures, forwards, and other contractual commitments, to manage its exposure to commodity prices. To the extent that these contracts are derivatives, MGE assesses whether or not the normal purchases or normal sales exclusion applies. For contracts to which this exclusion cannot be applied, the derivatives are recognized in the consolidated balance sheets at fair value. MGE's financial commodity derivative activities are conducted in accordance with its electric and gas risk management program, which is approved by the PSCW and limits the volume MGE can hedge with specific risk management strategies. The maximum length of time over which cash flows related to energy commodities can be hedged is four years. If the derivative qualifies for regulatory deferral, the derivatives are marked to fair value and are offset with a corresponding regulatory asset or liability depending on whether the derivative is in a net loss or net gain position, respectively. The deferred gain or loss is recognized in earnings in the delivery month applicable to the instrument. Gains and losses related to hedges qualifying for regulatory treatment are refundable or recoverable in gas rates through the Purchased Gas Adjustment (PGA) or in electric rates as a component of the fuel rules mechanism.

Derivative Netting

All derivative instruments in this table are presented on a gross basis and are calculated prior to the netting of instruments with the same counterparty under a master netting agreement as well as the netting of collateral. For financial statement purposes, instruments are netted with the same counterparty under a master netting agreement as well as the netting of collateral.

Recurring Fair Value Measurements

Fair value is defined as the price that would be received to sell an asset or would be paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants at the measurement date. The accounting standard clarifies that fair value should be based on the assumptions market participants would use when pricing the asset or liability including assumptions about risk. The standard also establishes a

three-level fair value hierarchy based upon the observability of the assumptions used and requires the use of observable market data when available. The levels are:

Level 1 - Pricing inputs are quoted prices within active markets for identical assets or liabilities.

Level 2 - Pricing inputs are quoted prices within active markets for similar assets or liabilities; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations that are correlated with or otherwise verifiable by observable market data.

Level 3 - Pricing inputs are unobservable and reflect management's best estimate of what market participants would use in pricing the asset or liability.

a.Fair Value of Financial Assets and Liabilities Recorded at the Carrying Amount.

The carrying amount of cash, cash equivalents, and outstanding commercial paper approximates fair market value due to the short maturity of those investments and obligations. The estimated fair market value of long-term debt is based on quoted market prices for similar financial instruments. Since long-term debt is not traded in an active market, it is classified as Level 2.Investments include exchange-traded investment securities valued using quoted prices on active exchanges and are therefore classified as Level 1.

Deferred Compensation. The deferred compensation plans allow participants to defer certain cash compensation into notional investment accounts. These amounts are included within "Other deferred liabilities and other" in the consolidated balance sheets. The value of certain deferred compensation obligations is based on the market value of the

participants' notional investment accounts. The underlying notional investments are comprised primarily of equities, mutual funds, and fixed income securities that are based on directly and indirectly observable market prices. Since the deferred compensation obligations themselves are not exchanged in an active market, they are classified as Level 2.

The value of legacy deferred compensation obligations is based on notional investments that earn interest based upon the semiannual rate of U.S. Treasury Bills having a 26-week maturity increased by 1% compounded monthly with a minimum annual rate of 7%, compounded monthly. The notional investments are based upon observable market data, however, since the deferred compensation obligations themselves are not exchanged in an active market, they are classified as Level 2.

Derivatives. Derivatives include exchange-traded derivative contracts, over-the-counter transactions, and FTRs. Most exchange-traded derivative contracts are valued based on unadjusted quoted prices in active markets and are therefore classified as Level 1. A small number of exchange-traded derivative contracts are valued using quoted market pricing in markets with insufficient volumes and are therefore considered unobservable and classified as Level 3. Transactions done with an over-the-counter party are on inactive markets and are therefore classified as Level 3. These transactions are valued based on quoted prices from markets with similar exchange-traded transactions. FTRs are priced based upon monthly auction results for identical or similar instruments in a closed market with limited data available and are therefore classified as Level 3.

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Summary of Significant Accounting Principles (Tables)

6 Months Ended

Jun. 30, 2025

Cash, Cash Equivalents, And Restricted Cash [Abstract]

Cash, Cash Equivalents, and Restricted Cash

The following table presents the components of total cash, cash equivalents, and restricted cash on the consolidated balance sheets.

	MGE Energy				MGE
	June 30,		December 31,		June 30,		December 31,
(In thousands)	2025		2024		2025		2024
Cash and cash equivalents	$	10,569	$	21,302	$	3,525	$	16,865
Restricted cash		869		1,113		869		1,113
Receivable - margin account		1,698		2,081		1,698		2,081
Cash, cash equivalents, and restricted cash	$	13,136	$	24,496	$	6,092	$	20,059

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Investment in ATC and ATC Holdco (Tables)

6 Months Ended

Jun. 30, 2025

Equity Method Investments and Joint Ventures [Abstract]

Equity Method Investments Financial Data

MGE Transco recorded the following amounts related to its investment in ATC:

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In thousands)	2025		2024		2025		2024
Equity earnings from investment in ATC	$	3,066	$	2,748	$	6,056	$	5,470
Dividends received from ATC		2,345		2,132		5,632		4,238
Capital contributions to ATC		2,679		1,070		5,171		1,785

ATC's summarized financial data is as follows:

	Three Months Ended						Six Months Ended
	June 30,						June 30,
(In thousands)	2025			2024			2025			2024
Operating revenues	$	241,227		$	218,222		$	476,156		$	430,150
Operating expenses		(117,564	)		(109,197	)		(234,309	)		(214,039	)
Other income, net		550			356			633			543
Interest expense, net		(43,254	)		(36,040	)		(82,447	)		(71,458	)
Earnings before members' income taxes	$	80,959		$	73,341		$	160,033		$	145,196

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Taxes (Tables)

6 Months Ended

Jun. 30, 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 June 30,	2025				2024				2025				2024
Statutory federal income tax rate		21.0		%		21.0		%		21.0		%		21.0		%
State income taxes, net of federal benefit		6.4				6.2				6.2				6.2
Amortized investment tax credits		(1.3	)			(2.4	)			(1.4	)			(2.6	)
Credit for electricity from renewable energy		(13.2	)			(11.7	)			(14.4	)			(12.9	)
AFUDC equity, net		(0.5	)			(0.7	)			(0.5	)			(0.7	)
Amortization of utility excess deferred tax - tax reform(a)		(2.5	)			(6.8	)			(2.7	)			(7.5	)
Other, net, individually insignificant		0.2				0.2				0.2				0.1
Effective income tax rate		10.1		%		5.8		%		8.4		%		3.6		%
	MGE Energy								MGE
Six Months Ended June 30,	2025				2024				2025				2024
Statutory federal income tax rate		21.0		%		21.0		%		21.0		%		21.0		%
State income taxes, net of federal benefit		6.3				6.2				6.2				6.2
Amortized investment tax credits		(1.3	)			(2.3	)			(1.5	)			(2.5	)
Credit for electricity from renewable energy		(11.0	)			(10.8	)			(11.9	)			(11.9	)
AFUDC equity, net		(0.6	)			(0.7	)			(0.6	)			(0.7	)
Amortization of utility excess deferred tax - tax reform(a)		(2.5	)			(6.4	)			(2.8	)			(7.0	)
Other, net, individually insignificant		0.1				(0.1	)			0.1				(0.2	)
Effective income tax rate		12.0		%		6.9		%		10.5		%		4.9		%

(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 June 30, 2025 and 2024, MGE recognized $0.9 million. For both the six months ended June 30, 2025 and 2024, MGE recognized $1.8 million. For the three and six months ended June 30, 2024, MGE recognized $1.0 million and $2.1 million, respectively, of deferred taxes not restricted by IRS normalization rules.

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Pension and Other Postretirement Plans (Tables)

6 Months Ended

Jun. 30, 2025

Retirement Benefits [Abstract]

Schedule of Net Periodic Benefit Costs

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

	Three Months Ended						Six Months Ended
	June 30,						June 30,
(In thousands)	2025			2024			2025			2024
Pension Benefits
Components of net periodic benefit cost:
Service cost	$	655		$	780		$	1,306		$	1,539
Interest cost		4,313			4,315			8,569			8,559
Expected return on assets		(7,246	)		(7,148	)		(14,507	)		(14,299	)
Amortization of:
Actuarial loss		102			313			150			429
Net periodic benefit (credit) cost	$	(2,176	)	$	(1,740	)	$	(4,482	)	$	(3,772	)
Postretirement Benefits
Components of net periodic benefit cost:
Service cost	$	188		$	217		$	371		$	428
Interest cost		754			779			1,514			1,576
Expected return on assets		(634	)		(693	)		(1,358	)		(1,384	)
Amortization of:
Transition obligation		—			—			1			1
Prior service credit		—			(4	)		—			(8	)
Actuarial gain		(173	)		(129	)		(321	)		(206	)
Net periodic benefit cost	$	135		$	170		$	207		$	407

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Commitments and Contingencies (Tables)

6 Months Ended

Jun. 30, 2025

Commitments and Contingencies Disclosure [Abstract]

Contractual Obligation, Fiscal Year Maturity Schedule

The following table shows future commitments related to purchase contracts as of June 30, 2025:

(In thousands)	2025		2026		2027		2028		2029		Thereafter
Coal(a)	$	9,437	$	8,387	$	4,043	$	4,126	$	—	$	—
Natural gas(b)		26,109		51,334		37,306		41,131		40,951		316,598
Renewable energy(c)		6,084		3,454		3,324		3,324		1,350		38,100
	$	41,630	$	63,175	$	44,673	$	48,581	$	42,301	$	354,698

(a)Total coal commitments for MGE's share of the Columbia and Elm Road Units, including transportation. Fuel procurement for MGE's jointly owned Columbia and Elm Road Units is handled by Wisconsin Power and Light Company and WEPCO, respectively, who are the operators of those facilities.

(b)MGE's natural gas transportation and storage contracts require fixed monthly payments for firm supply pipeline transportation and storage capacity. The pricing components of the fixed monthly payments for the transportation and storage contracts are approved by FERC but may be subject to change. MGE's natural gas supply commitments include market-based pricing.

(c)Operational commitments for solar and wind facilities.

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Rate Matters (Tables)

6 Months Ended

Jun. 30, 2025

Regulated Operations [Abstract]

Rate Proceedings

	Rate increase	Return on Common Equity	Common Equity Component of Regulatory Capital Structure	Effective Date
Approved 2024/2025 rate proceeding(a)(b)
Electric	1.54%	9.7%	56.1%	1/1/2024
Gas	2.44%	9.7%	56.1%	1/1/2024
Electric(c)	2.63%	9.7%	56.1%	1/1/2025
Gas	1.32%	9.7%	56.1%	1/1/2025
Proposed 2026/2027 rate proceeding(d)
Electric(e)	4.89%	10.0%	56.1%	1/1/2026
Gas(e)	2.33%	10.0%	56.1%	1/1/2026
Electric(f)	4.33%	10.0%	56.0%	1/1/2027
Gas(f)	2.16%	10.0%	56.0%	1/1/2027

(a)The electric rate increase was driven by an increase in rate base including our investments made in West Riverside, local solar, continued investment in grid modernization, as well as higher costs for transmission, pension and other post retirement benefits, and uncollectible costs (including costs previously deferred from prior years). This increase in electric costs is offset by a decrease in fuel costs and benefit from lower tax expense (including impacts from the Inflation Reduction Act). MGE filed an updated 2025 fuel forecast with the PSCW in 2024, which will impact rates in 2025, based on any variance between the forecast submitted as part of the rates and updated forecast. In addition, the PSCW authorized MGE to defer a recovery of and a return on costs associated for any change in the in-service date for Paris and force majeure costs for Badger Hollow II and Paris that were not reflected in this rate filing. The PSCW also approved deferral of any differential in PTC tax credits reflected in rates and actual credits produced. These deferrals will be reflected in MGE's next rate case filing. The gas rate increases were also driven by our investment made in grid modernization and higher pension and other post retirement benefits and uncollectible costs (including costs previously deferred from prior years). This increase in gas costs is offset by a tax benefit related to excess deferred taxes. Included in the gas residential rate is a reduction in the customer fixed charge.

(b)The 2024/2025 rate order includes an earnings sharing mechanism, under which, if MGE earns above the authorized Return on Equity (ROE) in the rate order: (i) the utility will retain 100.0% of earnings for the first 15 basis points above the authorized ROE; (ii) 50.0% of the next 60 basis points will be required to be deferred and returned to customers; and (iii) 100.0% of any remaining excess earnings will be required to be refunded to customers. The earnings calculation excludes fuel rules adjustments. See "Fuel Rules" below.

(c)The PSCW approved a 2025 Fuel Cost Plan in December 2024. The plan lowered the 2025 increase in electric rates to 2.63% to reflect lower expected fuel costs.

(d)In April 2025, MGE filed a proposed 2-year rate case and PSCW approval is pending. A final order is expected before the end of the year.

(e)The proposed electric rate increase reflects growth in rate base, primarily from investments in Paris (battery), Darien (battery), Sunnyside (solar), West Riverside, and continued investment in grid modernization, as well as higher costs for transmission. The increase in electric costs is offset by a decrease in fuel costs, changes in pension and other post retirement benefits, and benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas increase is driven by an increase in rate base including continued distribution infrastructure improvements designed to enhance reliability and safety and system modernization. The increase in gas costs is offset by changes in pension and other post retirement benefits.

(f)The proposed electric rate increase is driven by an increase in rate base including investments made in the Koshkonong (solar), Sunnyside (battery), and High Noon (solar/battery) projects, and continued investment in grid modernization projects. The increase in electric costs is offset by a benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas rate increase is driven by an increase in rate base.

Deferred Fuel Rules

The following table summarizes deferred electric fuel-related costs:

	Fuel Costs (Savings) (in millions)	Refund or Recovery Period
2022	$8.8(a)	October 2023 through September 2024
2023	($7.2)(a)	October 2024 through December 2024
2024	($3.0)(a)	October 2025
2025	($2.5)	(b)

(a)There was no change to the refund or recovery in the fuel rules proceedings from the amount MGE deferred.

(b)These costs will be subject to the PSCW's annual review of 2025 fuel costs, expected to be completed in 2026.

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Derivative and Hedging Instruments (Tables)

6 Months Ended

Jun. 30, 2025

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Gross Notional Volume of Open Derivatives

The gross notional volume of open derivatives is as follows:

	June 30, 2025			December 31, 2024
Commodity derivative contracts		279,520	MWh		307,640	MWh
Commodity derivative contracts		6,662,500	Dth		6,285,000	Dth
FTRs		5,159	MW		2,131	MW

Fair Value of Derivative Instruments on the Balance Sheet

The following table summarizes the fair value of the derivative instruments on the consolidated balance sheets. All derivative instruments in this table are presented on a gross basis and are calculated prior to the netting of instruments with the same counterparty under a master netting agreement as well as the netting of collateral. For financial statement purposes, instruments are netted with the same counterparty under a master netting agreement as well as the netting of collateral.

	Derivative		Derivative
(In thousands)	Assets		Liabilities		Balance Sheet Location
June 30, 2025
Commodity derivative contracts(a)	$	1,455	$	1,192	Other current assets
Commodity derivative contracts(a)		223		47	Other deferred charges
FTRs		258		—	Other current assets
December 31, 2024
Commodity derivative contracts(a)	$	927	$	1,121	Other current liabilities
Commodity derivative contracts(a)		286		140	Other deferred liabilities and other
FTRs		108		—	Other current assets

(a)As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

Offsetting Assets

The following table shows the effect of netting arrangements for recognized derivative assets and liabilities that are subject to a master netting arrangement or similar arrangement on the consolidated balance sheets.

Offsetting of Derivative Assets and Liabilities

(In thousands)	Gross Amounts		Gross Amounts Offset in Balance Sheets			Collateral Posted Against Derivative Positions			Net Amount Presented in Balance Sheets
June 30, 2025
Assets
Commodity derivative contracts	$	1,678	$	(1,239	)	$	—		$	439
FTRs		258		—			—			258
Liabilities
Commodity derivative contracts		1,239		(1,239	)		—			—
December 31, 2024
Assets
Commodity derivative contracts	$	1,213	$	(1,213	)	$	—		$	—
FTRs		108		—			—			108
Liabilities
Commodity derivative contracts		1,261		(1,213	)		(48	)		—

Offsetting Liabilities

The following table shows the effect of netting arrangements for recognized derivative assets and liabilities that are subject to a master netting arrangement or similar arrangement on the consolidated balance sheets.

Offsetting of Derivative Assets and Liabilities

(In thousands)	Gross Amounts		Gross Amounts Offset in Balance Sheets			Collateral Posted Against Derivative Positions			Net Amount Presented in Balance Sheets
June 30, 2025
Assets
Commodity derivative contracts	$	1,678	$	(1,239	)	$	—		$	439
FTRs		258		—			—			258
Liabilities
Commodity derivative contracts		1,239		(1,239	)		—			—
December 31, 2024
Assets
Commodity derivative contracts	$	1,213	$	(1,213	)	$	—		$	—
FTRs		108		—			—			108
Liabilities
Commodity derivative contracts		1,261		(1,213	)		(48	)		—

Derivative Gains and Losses in Balance Sheet

The following tables summarize the unrealized and realized gains/losses related to the derivative instruments on the consolidated balance sheets and the consolidated statements of income.

	2025						2024
(In thousands)	Current and Long-Term Regulatory Asset (Liability)			Other Current Assets			Current and Long-Term Regulatory Asset (Liability)			Other Current Assets
Three Months Ended June 30:
Balance as of April 1,	$	(1,860	)	$	78		$	3,009		$	275
Unrealized loss		2,118			—			758			—
Realized (loss) gain reclassified to a deferred account		(288	)		288			(537	)		537
Realized (loss) gain reclassified to income statement		(667	)		30			(1,284	)		(285	)
Balance as of June 30,	$	(697	)	$	396		$	1,946		$	527
Six Months Ended June 30:
Balance as of January 1,	$	(60	)	$	388		$	5,226		$	1,569
Unrealized loss		362			—			2,898			—
Realized (loss) gain reclassified to a deferred account		263			(263	)		(2,694	)		2,694
Realized (loss) gain reclassified to income statement		(1,262	)		271			(3,484	)		(3,736	)
Balance as of June 30,	$	(697	)	$	396		$	1,946		$	527

Derivative Gains and Losses in Income Statement

	Realized Losses (Gains)
	2025					2024
(In thousands)	Fuel for Electric Generation/ Purchased Power		Cost of Gas Sold			Fuel for Electric Generation/ Purchased Power		Cost of Gas Sold
Three Months Ended June 30:
Commodity derivative contracts	$	198	$	—		$	1,328	$	—
FTRs		439		—			241		—
Six Months Ended June 30:
Commodity derivative contracts	$	596	$	(203	)	$	3,754	$	3,265
FTRs		598		—			201		—

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Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2025

Fair Value Disclosures [Abstract]

Estimated Fair Market Value of Financial Instruments

The estimated fair market value of financial instruments are as follows:

	June 30, 2025				December 31, 2024
(In thousands)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt(a)	$	770,775	$	710,479	$	773,400	$	698,765

(a)Includes long-term debt due within one year. Excludes debt issuance costs and unamortized discount of $4.1 million and $4.4 million as of June 30, 2025, and December 31, 2024, respectively.

Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents the balances of assets and liabilities measured at fair value on a recurring basis for both MGE and MGE Energy.

	Fair Value as of June 30, 2025
(In thousands)	Total		Level 1		Level 2		Level 3
Assets:
Derivatives, net(b)	$	1,936	$	1,416	$	—	$	520
Liabilities:
Derivatives, net(b)	$	1,239	$	916	$	—	$	323
Deferred compensation		6,753		—		6,753		—
Total Liabilities	$	7,992	$	916	$	6,753	$	323

	Fair Value as of December 31, 2024
(In thousands)	Total		Level 1		Level 2		Level 3
Assets:
Derivatives, net(b)	$	1,321	$	987	$	—	$	334
Liabilities:
Derivatives, net(b)	$	1,261	$	480	$	—	$	781
Deferred compensation		6,468		—		6,468		—
Total Liabilities	$	7,729	$	480	$	6,468	$	781

(b)As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

Changes in Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table summarizes the changes in Level 3 commodity derivative assets and liabilities measured at fair value on a recurring basis.

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In thousands)	2025		2024		2025		2024
Beginning balance	$	515	$	(1,726)	$	(447)	$	(2,604)
Realized and unrealized gains (losses):
Included in regulatory assets		—		294		—		1,172
Included in regulatory liability		(318)		—		642		—
Included in earnings		(665)		(1,330)		(1,262)		(3,855)
Settlements		665		1,330		1,264		3,855
Balance as of June 30,	$	197	$	(1,432)	$	197	$	(1,432)

Gains and Losses Included in Income for Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis

The following table presents total realized and unrealized gains (losses) included in income for Level 3 assets and liabilities measured at fair value on a recurring basis(c).

	Three Months Ended				Six Months Ended
	June 30,				June 30,
(In thousands)	2025		2024		2025		2024
Purchased power expense	$	(665)	$	(1,330)	$	(1,262)	$	(3,855)

(c)MGE's exchange-traded derivative contracts, over-the-counter party transactions, purchased power agreement, and FTRs are subject to regulatory deferral. These derivatives are therefore marked to fair value and are offset in the financial statements with a corresponding regulatory asset or liability.

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Joint Plant (Tables)

6 Months Ended

Jun. 30, 2025

Public Utilities, Property, Plant and Equipment [Abstract]

Schedule of Jointly Owned Utility Plants

MGE has ownership interests in generation projects with other co-owners, some of which are under construction, as shown in the following table. Incurred costs are reflected in "Property, plant, and equipment, net" or "Construction work in progress" on the consolidated balance sheets.

Project	Ownership Interest	Source	Share of Generation	Share of Estimated Costs(a)	Costs incurred as of June 30, 2025(a)	Date of Commercial Operation
Paris(b)	10%	Battery	11 MW	$25 million(g)	$23.4 million	June 2025 Battery
Darien(c)	10%	Solar/Battery	25 MW/7.5 MW	$63 million(g)	$46.3 million	March 2025 Solar 2026 Battery(h)
Koshkonong(d)	10%	Solar/Battery	30 MW/16.5 MW	$104 million(g)	$24.8 million	2026 Solar(h) 2027 Battery(h)
High Noon(e)	10%	Solar/Battery	30 MW/16.5 MW	$99 million	$17.8 million	2027(h)
Columbia Energy Dome(f)	19%	Storage	3 MW	$17 million	$0.7 million	2027(h)

(a)Excluding AFUDC.

(b)Paris Solar-Battery Park is located in the Town of Paris in Kenosha County, Wisconsin.

(c)Darien Solar Energy Center is located in Walworth and Rock Counties in southern Wisconsin.

(d)Koshkonong Solar Energy Center is located in the Towns of Christiana and Deerfield in Dane County, Wisconsin.

(e)High Noon Solar Project is located in Columbia County, Wisconsin.

(f)Columbia Energy Dome is located in Columbia County, Wisconsin.

(g)Estimated costs are expected to exceed PSCW previously approved Certificate of Authority (CA) levels. Notifications are provided to the PSCW when costs increase above CA levels. MGE has and will continue to request recovery of the updates in its rate case proceedings.

(h)Estimated date of commercial operation.

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Revenue (Tables)

6 Months Ended

Jun. 30, 2025

Revenue from Contract with Customer [Abstract]

Disaggregation of Revenue

Revenues disaggregated by revenue source were as follows:

	Three Months Ended				Six Months Ended
(In thousands)	June 30,				June 30,
Electric revenues	2025		2024		2025		2024
Residential	$	43,182	$	40,321	$	88,321	$	81,462
Commercial		64,027		64,161		124,662		124,024
Industrial		3,117		3,445		6,081		6,855
Other-retail/municipal		10,342		10,403		19,690		20,093
Total retail		120,668		118,330		238,754		232,434
Sales to the market		7,840		1,519		14,320		2,595
Other		805		534		1,693		1,479
Total electric revenues		129,313		120,383		254,767		236,508
Gas revenues
Residential		17,956		15,589		71,824		58,987
Commercial/Industrial		10,434		7,876		47,547		37,400
Total retail		28,390		23,465		119,371		96,387
Gas transportation		1,384		1,505		3,697		3,585
Other		151		146		338		313
Total gas revenues		29,925		25,116		123,406		100,285
Non-regulated energy revenues		214		214		249		256
Total Operating Revenue	$	159,452	$	145,713	$	378,422	$	337,049

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Segment Information (Tables)

6 Months Ended

Jun. 30, 2025

Segment Reporting [Abstract]

Segment Information

The following table shows segment information for MGE Energy's and MGE's operations:

(In thousands) MGE Energy	Electric			Gas			Non-Regulated Energy			Transmission Investment			Total Reportable Segments			All Others			Consolidation/ Elimination			Consolidated Total
Three Months Ended June 30, 2025
Operating revenues	$	129,313		$	29,925		$	214		$	—		$	159,452		$	—		$	—		$	159,452
Interdepartmental revenues		(28	)		2,558			11,121			—			13,651			—			(13,651	)		—
Total operating revenues		129,285			32,483			11,335			—			173,103			—			(13,651	)		159,452
Fuel and purchased power		(22,524	)		—			—			—			(22,524	)		—			670			(21,854	)
Purchased gas costs		—			(13,211	)		—			—			(13,211	)		—			1,898			(11,313	)
Depreciation and amortization		(22,094	)		(4,347	)		(1,913	)		—			(28,354	)		—			—			(28,354	)
Interest expense		(6,485	)		(1,768	)		(889	)		—			(9,142	)		—			—			(9,142	)
Other segment items(a)		(58,130	)		(15,015	)		(23	)		—			(73,168	)		(291	)		11,083			(62,376	)
Income tax (provision) benefit		(472	)		561			(2,318	)		(835	)		(3,064	)		89			—			(2,975	)
Equity in earnings of investments		—			—			—			3,060			3,060			—			—			3,060
Net income (loss)		19,580			(1,297	)		6,192			2,225			26,700			(202	)		—			26,498
Three Months Ended June 30, 2024
Operating revenues	$	120,383		$	25,116		$	214		$	—		$	145,713		$	—		$	—		$	145,713
Interdepartmental revenues		(55	)		2,172			10,946			—			13,063			—			(13,063	)		—
Total operating revenues		120,328			27,288			11,160			—			158,776			—			(13,063	)		145,713
Fuel and purchased power		(20,840	)		—			—			—			(20,840	)		—			753			(20,087	)
Purchased gas costs		—			(7,720	)		—			—			(7,720	)		—			1,427			(6,293	)
Depreciation and amortization		(20,888	)		(4,163	)		(1,881	)		—			(26,932	)		—			—			(26,932	)
Interest expense		(6,323	)		(1,709	)		(957	)		—			(8,989	)		—			—			(8,989	)
Other segment items(a)		(57,257	)		(14,456	)		(17	)		—			(71,730	)		(79	)		10,883			(60,926	)
Income tax (provision) benefit		641			810			(2,262	)		(758	)		(1,569	)		97			—			(1,472	)
Equity in earnings of investments		—			—			—			2,780			2,780			—			—			2,780
Net income		15,661			50			6,043			2,022			23,776			18			—			23,794
Six Months Ended June 30, 2025
Operating revenues	$	254,767		$	123,406		$	249		$	—		$	378,422		$	—		$	—		$	378,422
Interdepartmental revenues		(76	)		9,030			22,225			—			31,179			—			(31,179	)		—
Total operating revenues		254,691			132,436			22,474			—			409,601			—			(31,179	)		378,422
Fuel and purchased power		(45,630	)		—			—			—			(45,630	)		—			1,829			(43,801	)
Purchased gas costs		—			(72,501	)		—			—			(72,501	)		—			7,224			(65,277	)
Depreciation and amortization		(43,629	)		(8,579	)		(3,824	)		—			(56,032	)		—			—			(56,032	)
Interest expense		(12,978	)		(3,531	)		(1,795	)		—			(18,304	)		—			—			(18,304	)
Other segment items(a)		(114,109	)		(31,111	)		(67	)		—			(145,287	)		(727	)		22,126			(123,888	)
Income tax (provision) benefit		1,430			(4,426	)		(4,573	)		(1,702	)		(9,271	)		—			—			(9,271	)
Equity in earnings of investments		—			—			—			6,241			6,241			—			—			6,241
Net income (loss)		39,775			12,288			12,215			4,539			68,817			(727	)		—			68,090
Six Months Ended June 30, 2024
Operating revenues	$	236,508		$	100,285		$	256		$	—		$	337,049		$	—		$	—		$	337,049
Interdepartmental revenues		(109	)		7,383			21,773			—			29,047			—			(29,047	)		—
Total operating revenues		236,399			107,668			22,029			—			366,096			—			(29,047	)		337,049
Fuel and purchased power		(43,910	)		—			—			—			(43,910	)		—			1,677			(42,233	)
Purchased gas costs		—			(53,893	)		—			—			(53,893	)		—			5,723			(48,170	)
Depreciation and amortization		(41,538	)		(8,245	)		(3,749	)		—			(53,532	)		—			—			(53,532	)
Interest expense		(12,651	)		(3,419	)		(1,931	)		—			(18,001	)		—			—			(18,001	)
Other segment items(a)		(110,802	)		(29,161	)		(41	)		(2	)		(140,006	)		(392	)		21,647			(118,751	)
Income tax (provision) benefit		3,926			(2,286	)		(4,442	)		(1,506	)		(4,308	)		28			—			(4,280	)
Equity in earnings of investments		—			—			—			5,526			5,526			—			—			5,526
Net income (loss)		31,424			10,664			11,866			4,018			57,972			(364	)		—			57,608

(a)Other segment items include AFUDC Income, Other Income, Net, Other Operations and Maintenance, Other General Taxes, and Interest Revenue.

(In thousands) MGE	Electric			Gas			Non-Regulated Energy			Total Reportable Segments			Consolidation/ Elimination			Consolidated Total
Three Months Ended June 30, 2025
Operating revenues	$	129,313		$	29,925		$	214		$	159,452		$	—		$	159,452
Interdepartmental revenues		(28	)		2,558			11,121			13,651			(13,651	)		—
Total operating revenues		129,285			32,483			11,335			173,103			(13,651	)		159,452
Fuel and purchased power		(22,524	)		—			—			(22,524	)		670			(21,854	)
Purchased gas costs		—			(13,211	)		—			(13,211	)		1,898			(11,313	)
Depreciation and amortization		(22,094	)		(4,347	)		(1,913	)		(28,354	)		—			(28,354	)
Interest expense		(6,485	)		(1,768	)		(889	)		(9,142	)		—			(9,142	)
Other segment items(a)		(58,130	)		(15,015	)		(23	)		(73,168	)		11,083			(62,085	)
Income tax benefit (provision)		(472	)		561			(2,318	)		(2,229	)		—			(2,229	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(5,714	)		(5,714	)
Net income attributable to MGE		19,580			(1,297	)		6,192			24,475			(5,714	)		18,761
Three Months Ended June 30, 2024
Operating revenues	$	120,383		$	25,116		$	214		$	145,713		$	—		$	145,713
Interdepartmental revenues		(55	)		2,172			10,946			13,063			(13,063	)		—
Total operating revenues		120,328			27,288			11,160			158,776			(13,063	)		145,713
Fuel and purchased power		(20,840	)		—			—			(20,840	)		753			(20,087	)
Purchased gas costs		—			(7,720	)		—			(7,720	)		1,427			(6,293	)
Depreciation and amortization		(20,888	)		(4,163	)		(1,881	)		(26,932	)		—			(26,932	)
Interest expense		(6,323	)		(1,709	)		(957	)		(8,989	)		—			(8,989	)
Other segment items(a)		(57,257	)		(14,456	)		(17	)		(71,730	)		10,883			(60,847	)
Income tax benefit (provision)		641			810			(2,262	)		(811	)		—			(811	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(5,766	)		(5,766	)
Net income attributable to MGE		15,661			50			6,043			21,754			(5,766	)		15,988
Six Months Ended June 30, 2025
Operating revenues	$	254,767		$	123,406		$	249		$	378,422		$	—		$	378,422
Interdepartmental revenues		(76	)		9,030			22,225			31,179			(31,179	)		—
Total operating revenues		254,691			132,436			22,474			409,601			(31,179	)		378,422
Fuel and purchased power		(45,630	)		—			—			(45,630	)		1,829			(43,801	)
Purchased gas costs		—			(72,501	)		—			(72,501	)		7,224			(65,277	)
Depreciation and amortization		(43,629	)		(8,579	)		(3,824	)		(56,032	)		—			(56,032	)
Interest expense		(12,978	)		(3,531	)		(1,795	)		(18,304	)		—			(18,304	)
Other segment items(a)		(114,109	)		(31,111	)		(67	)		(145,287	)		22,126			(123,161	)
Income tax benefit (provision)		1,430			(4,426	)		(4,573	)		(7,569	)		—			(7,569	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(11,313	)		(11,313	)
Net income attributable to MGE		39,775			12,288			12,215			64,278			(11,313	)		52,965
Six Months Ended June 30, 2024
Operating revenues	$	236,508		$	100,285		$	256		$	337,049		$	—		$	337,049
Interdepartmental revenues		(109	)		7,383			21,773			29,047			(29,047	)		—
Total operating revenues		236,399			107,668			22,029			366,096			(29,047	)		337,049
Fuel and purchased power		(43,910	)		—			—			(43,910	)		1,677			(42,233	)
Purchased gas costs		—			(53,893	)		—			(53,893	)		5,723			(48,170	)
Depreciation and amortization		(41,538	)		(8,245	)		(3,749	)		(53,532	)		—			(53,532	)
Interest expense		(12,651	)		(3,419	)		(1,931	)		(18,001	)		—			(18,001	)
Other segment items(a)		(110,802	)		(29,161	)		(41	)		(140,004	)		21,647			(118,357	)
Income tax benefit (provision)		3,926			(2,286	)		(4,442	)		(2,802	)		—			(2,802	)
Net income attributable to noncontrolling interest, net of tax		—			—			—			—			(11,363	)		(11,363	)
Net income attributable to MGE		31,424			10,664			11,866			53,954			(11,363	)		42,591

(a)Other segment items include AFUDC Income, Other Income, Net, Other Operations and Maintenance, Other General Taxes, and Interest Revenue.

The following table shows segment information for MGE Energy's and MGE's capital expenditures:

	Utility				Consolidated
(In thousands) MGE Energy	Electric		Gas		Non-regulated Energy		Transmission Investment		All Others		Consolidation/ Elimination Entries		Total
Six Months Ended June 30, 2025	$	83,034	$	22,975	$	5,744	$	—	$	—	$	—	$	111,753
Six Months Ended June 30, 2024		86,755		20,879		3,988		—		—		—		111,622

	Utility				Consolidated
(In thousands) MGE	Electric		Gas		Non-regulated Energy		Consolidation/ Elimination Entries		Total
Six Months Ended June 30, 2025	$	83,034	$	22,975	$	5,744	$	—	$	111,753
Six Months Ended June 30, 2024		86,755		20,879		3,988		—		111,622

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Summary of Significant Accounting Principles (Details-1) - USD ($) $ in Thousands	Jun. 30, 2025	Dec. 31, 2024	Jun. 30, 2024	Dec. 31, 2023
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	$ 10,569	$ 21,302
Restricted cash	869	1,113
Receivable - margin account	1,698	2,081
Cash, cash equivalents, and restricted cash	13,136	24,496	$ 19,537	$ 15,026
MGE [Member]
Cash Cash Equivalents And Restricted Cash [Line Items]
Cash and cash equivalents	3,525	16,865
Restricted cash	869	1,113
Receivable - margin account	1,698	2,081
Cash, cash equivalents, and restricted cash	$ 6,092	$ 20,059	$ 7,134	$ 6,705

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Summary of Significant Accounting Principles (Details-2) $ in Millions	6 Months Ended
	Jun. 30, 2025 USD ($)
Columbia Units [Member]
Impairment of Long-Lived Assets
Impairment of long-lived assets	$ 0

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Investment in ATC and ATC Holdco (Details-1) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jul. 31, 2025	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Schedule of Equity Method Investments [Line Items]
Equity earnings from investment				$ 6,241	$ 5,526
Dividends from investments				6,008	4,238
Capital contributions to investments				5,871	3,159
MGE Transco [Member] | ATC [Member]
Schedule of Equity Method Investments [Line Items]
Equity earnings from investment		$ 3,066	$ 2,748	6,056	5,470
Dividends from investments		2,345	2,132	5,632	4,238
Capital contributions to investments		$ 2,679	$ 1,070	$ 5,171	$ 1,785
MGE Transco [Member] | ATC [Member] | Subsequent Event [Member]
Schedule of Equity Method Investments [Line Items]
Capital contributions to investments	$ 3,200

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Investment in ATC and ATC Holdco (Details-2) - ATC [Member] - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Schedule of Equity Method Investments [Line Items]
Operating revenues	$ 241,227	$ 218,222	$ 476,156	$ 430,150
Operating expenses	(117,564)	(109,197)	(234,309)	(214,039)
Other income, net	550	356	633	543
Interest expense, net	(43,254)	(36,040)	(82,447)	(71,458)
Earnings before members' income taxes	$ 80,959	$ 73,341	$ 160,033	$ 145,196

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Investment in ATC and ATC Holdco (Details-3) - ATC [Member] - Affiliated Entity [Member] - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024
Receivables [Abstract]
Other Receivables	$ 0.5		$ 0.5		$ 2.0
Operating Costs and Expenses [Abstract]
Operating Costs and Expenses, Total	$ 10.2	$ 9.1	$ 20.4	$ 18.2

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Taxes (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory federal income tax rate		21.00%	21.00%	21.00%	21.00%
State income taxes, net of federal benefit		6.40%	6.20%	6.30%	6.20%
Amortized investment tax credits		(1.30%)	(2.40%)	(1.30%)	(2.30%)
Credit for electricity from renewable energy		(13.20%)	(11.70%)	(11.00%)	(10.80%)
AFUDC equity, net		(0.50%)	(0.70%)	(0.60%)	(0.70%)
Amortization of utility excess deferred tax - tax reform	[1]	(2.50%)	(6.80%)	(2.50%)	(6.40%)
Other, net, individually insignificant		0.20%	0.20%	0.10%	(0.10%)
Effective income tax rate		10.10%	5.80%	12.00%	6.90%
Excess Deferred Taxes, Tax Cuts And Jobs Act [Member]
Effects Of The Tax Cuts And Jobs Act [Abstract]
Excess deferred tax - Income statement effect		$ 0.9	$ 0.9	$ 1.8	$ 1.8
Deficient Deferred Taxes, Tax Cuts And Jobs Act [Member]
Effects Of The Tax Cuts And Jobs Act [Abstract]
Collection of unprotected deficient deferred taxes			$ 1.0		$ 2.1
MGE [Member]
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory federal income tax rate		21.00%	21.00%	21.00%	21.00%
State income taxes, net of federal benefit		6.20%	6.20%	6.20%	6.20%
Amortized investment tax credits		(1.40%)	(2.60%)	(1.50%)	(2.50%)
Credit for electricity from renewable energy		(14.40%)	(12.90%)	(11.90%)	(11.90%)
AFUDC equity, net		(0.50%)	(0.70%)	(0.60%)	(0.70%)
Amortization of utility excess deferred tax - tax reform	[1]	(2.70%)	(7.50%)	(2.80%)	(7.00%)
Other, net, individually insignificant		0.20%	0.10%	0.10%	(0.20%)
Effective income tax rate		8.40%	3.60%	10.50%	4.90%

[1] 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 June 30, 2025 and 2024, MGE recognized $0.9 million. For both the six months ended June 30, 2025 and 2024, MGE recognized $1.8 million. For the three and six months ended June 30, 2024, MGE recognized $1.0 million and $2.1 million, respectively, of deferred taxes not restricted by IRS normalization rules.

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Pension and Other Postretirement Plans (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Defined Benefit Plan Deferred Pension And Other Postretirement Benefit Plan Costs Recovered [Abstract]
Deferred (recognized) pension and OPEB costs	$ (100)	$ (1,200)	$ (700)	$ (2,600)
Pension Benefits [Member]
Components of net periodic benefit cost:
Service cost	655	780	1,306	1,539
Interest cost	4,313	4,315	8,569	8,559
Expected return on assets	(7,246)	(7,148)	(14,507)	(14,299)
Amortization of:
Actuarial (gain) loss	102	313	150	429
Net periodic benefit (credit) cost	(2,176)	(1,740)	(4,482)	(3,772)
Postretirement Benefits [Member]
Components of net periodic benefit cost:
Service cost	188	217	371	428
Interest cost	754	779	1,514	1,576
Expected return on assets	(634)	(693)	(1,358)	(1,384)
Amortization of:
Transition obligation	0	0	1	1
Prior service credit	0	(4)	0	(8)
Actuarial (gain) loss	(173)	(129)	(321)	(206)
Net periodic benefit (credit) cost	$ 135	$ 170	$ 207	$ 407

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Equity and Financing Arrangements (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024
Common Stock [Abstract]
Stock Issued During Period, Shares, Dividend Reinvestment Plan	40,995
Issuance of common stock, net	$ 3,750	$ 0
Dilutive Shares Calculation [Abstract]
Shares included in diluted earnings per share	30,803

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Share Based Compensation (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended			6 Months Ended
	Mar. 31, 2025	Jun. 30, 2025	Mar. 31, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Compensation expense		$ 0.5		$ 0.7	$ 1.7	$ 1.9
2021 Long Term Incentive Plan [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Equity-based compensation plans and other - Shares			11,213
Cash payments distributed related to awards previously granted and now payable			$ 2.0
2021 Long Term Incentive Plan [Member] | Performance Shares [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period	18,136
2021 Long Term Incentive Plan [Member] | Restricted Units [Member]
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Share-Based Compensation Arrangement by Share-Based Payment Award, Equity Instruments Other than Options, Grants in Period	26,398

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Commitments and Contingencies (Details-2) $ in Thousands	Jun. 30, 2025 USD ($)
Operating expense purchase contracts [Abstract]
Purchase obligation, 2025	$ 41,630
Purchase obligation, 2026	63,175
Purchase obligation, 2027	44,673
Purchase obligation, 2028	48,581
Purchase obligation, 2029	42,301
Purchase obligation, Thereafter	354,698
Coal [Member]
Operating expense purchase contracts [Abstract]
Purchase obligation, 2025	9,437	[1]
Purchase obligation, 2026	8,387	[1]
Purchase obligation, 2027	4,043	[1]
Purchase obligation, 2028	4,126	[1]
Purchase obligation, 2029	0	[1]
Purchase obligation, Thereafter	0	[1]
Natural Gas [Member]
Operating expense purchase contracts [Abstract]
Purchase obligation, 2025	26,109	[2]
Purchase obligation, 2026	51,334	[2]
Purchase obligation, 2027	37,306	[2]
Purchase obligation, 2028	41,131	[2]
Purchase obligation, 2029	40,951	[2]
Purchase obligation, Thereafter	316,598	[2]
Renewable energy [Member]
Operating expense purchase contracts [Abstract]
Purchase obligation, 2025	6,084	[3]
Purchase obligation, 2026	3,454	[3]
Purchase obligation, 2027	3,324	[3]
Purchase obligation, 2028	3,324	[3]
Purchase obligation, 2029	1,350	[3]
Purchase obligation, Thereafter	$ 38,100	[3]

[1] Total coal commitments for MGE's share of the Columbia and Elm Road Units, including transportation. Fuel procurement for MGE's jointly owned Columbia and Elm Road Units is handled by Wisconsin Power and Light Company and WEPCO, respectively, who are the operators of those facilities.

[2] MGE's natural gas transportation and storage contracts require fixed monthly payments for firm supply pipeline transportation and storage capacity. The pricing components of the fixed monthly payments for the transportation and storage contracts are approved by FERC but may be subject to change. MGE's natural gas supply commitments include market-based pricing.

[3] Operational commitments for solar and wind facilities.

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Rate Matters (Details) - USD ($) $ in Millions		6 Months Ended		12 Months Ended
		Jun. 30, 2025		Dec. 31, 2027		Dec. 31, 2026		Dec. 31, 2024		Dec. 31, 2023	[2]	Dec. 31, 2022	[2]
Fuel Rules [Abstract]
Deferred fuel rules monitored costs		$ 2.5	[1]					$ 3.0	[2]	$ 7.2		$ (8.8)
Electric Rate Proceeding [Member] | PSCW [Member] | MGE [Member]
Rate Proceedings [Abstract]
Authorized rate increase (decrease), percentage	[3],[5]	2.63%	[4]					1.54%
Authorized return on equity, percentage		9.70%						9.70%
Approved equity capital structure, percentage		56.10%						56.10%
Fuel Rules [Abstract]
Fuel rules, bandwidth		2.00%						2.00%
Electric Rate Proceeding [Member] | PSCW [Member] | Rate Matters For Future Periods [Member] | MGE [Member]
Rate Proceedings [Abstract]
Proposed rate increase (decrease), percentage	[6]			4.33%	[7]	4.89%	[8]
Proposed return on equity, percentage				10.00%		10.00%
Proposed equity capital structure, percentage				56.00%		56.10%
Gas Rate Proceeding [Member] | PSCW [Member] | MGE [Member]
Rate Proceedings [Abstract]
Authorized rate increase (decrease), percentage	[3],[5]	1.32%						2.44%
Authorized return on equity, percentage		9.70%						9.70%
Approved equity capital structure, percentage		56.10%						56.10%
Gas Rate Proceeding [Member] | PSCW [Member] | Rate Matters For Future Periods [Member] | MGE [Member]
Rate Proceedings [Abstract]
Proposed rate increase (decrease), percentage	[6]			2.16%	[7]	2.33%	[8]
Proposed return on equity, percentage				10.00%		10.00%
Proposed equity capital structure, percentage				56.00%		56.10%

[1] These costs will be subject to the PSCW's annual review of 2025 fuel costs, expected to be completed in 2026.

[2] There was no change to the refund or recovery in the fuel rules proceedings from the amount MGE deferred.

[3] The 2024/2025 rate order includes an earnings sharing mechanism, under which, if MGE earns above the authorized Return on Equity (ROE) in the rate order: (i) the utility will retain 100.0% of earnings for the first 15 basis points above the authorized ROE; (ii) 50.0% of the next 60 basis points will be required to be deferred and returned to customers; and (iii) 100.0% of any remaining excess earnings will be required to be refunded to customers. The earnings calculation excludes fuel rules adjustments. See "Fuel Rules" below.

[4] The PSCW approved a 2025 Fuel Cost Plan in December 2024. The plan lowered the 2025 increase in electric rates to 2.63% to reflect lower expected fuel costs.

[5] The electric rate increase was driven by an increase in rate base including our investments made in West Riverside, local solar, continued investment in grid modernization, as well as higher costs for transmission, pension and other post retirement benefits, and uncollectible costs (including costs previously deferred from prior years). This increase in electric costs is offset by a decrease in fuel costs and benefit from lower tax expense (including impacts from the Inflation Reduction Act). MGE filed an updated 2025 fuel forecast with the PSCW in 2024, which will impact rates in 2025, based on any variance between the forecast submitted as part of the rates and updated forecast. In addition, the PSCW authorized MGE to defer a recovery of and a return on costs associated for any change in the in-service date for Paris and force majeure costs for Badger Hollow II and Paris that were not reflected in this rate filing. The PSCW also approved deferral of any differential in PTC tax credits reflected in rates and actual credits produced. These deferrals will be reflected in MGE's next rate case filing. The gas rate increases were also driven by our investment made in grid modernization and higher pension and other post retirement benefits and uncollectible costs (including costs previously deferred from prior years). This increase in gas costs is offset by a tax benefit related to excess deferred taxes. Included in the gas residential rate is a reduction in the customer fixed charge.

[6] In April 2025, MGE filed a proposed 2-year rate case and PSCW approval is pending. A final order is expected before the end of the year.

[7] The proposed electric rate increase is driven by an increase in rate base including investments made in the Koshkonong (solar), Sunnyside (battery), and High Noon (solar/battery) projects, and continued investment in grid modernization projects. The increase in electric costs is offset by a benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas rate increase is driven by an increase in rate base.

[8] The proposed electric rate increase reflects growth in rate base, primarily from investments in Paris (battery), Darien (battery), Sunnyside (solar), West Riverside, and continued investment in grid modernization, as well as higher costs for transmission. The increase in electric costs is offset by a decrease in fuel costs, changes in pension and other post retirement benefits, and benefit from lower tax expense (including impacts from the Inflation Reduction Act). The proposed gas increase is driven by an increase in rate base including continued distribution infrastructure improvements designed to enhance reliability and safety and system modernization. The increase in gas costs is offset by changes in pension and other post retirement benefits.

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Derivative and Hedging Instruments (Details-1) $ in Thousands		6 Months Ended	12 Months Ended
		Jun. 30, 2025 USD ($) Dth1 MWh MW	Dec. 31, 2024 USD ($) Dth1 MWh MW
Derivative fair values [Abstract]
Derivative, right to reclaim collateral			$ 100
Commodity Contracts And Financial Transimission Rights [Member]
Derivative fair values [Abstract]
Derivative, Fair Value, Net		$ 700	$ 100
Commodity Contract [Member]
Gross Notional Volume of Open Derivatives [Abstract]
Notional amount, energy measures (in MWh) | MWh		279,520	307,640
Notional amount, decatherm measure (in Dth) | Dth1		6,662,500	6,285,000
Derivative fair values [Abstract]
Derivative Asset, Fair Value, Gross Asset		$ 1,678	$ 1,213
Derivative Liability, Fair Value, Gross Liability		1,239	1,261
Collateral posted against derivative positions		0	0
Derivative, right to reclaim collateral		0	48
Commodity Contract [Member] | Other Current Assets/Liabilities
Derivative fair values [Abstract]
Derivative Asset, Fair Value, Gross Asset	[1]	1,455
Derivative Liability, Fair Value, Gross Liability	[1]	1,192
Commodity Contract [Member] | Other Deferred Charges [Member]
Derivative fair values [Abstract]
Derivative Asset, Fair Value, Gross Asset	[1]	223
Derivative Liability, Fair Value, Gross Liability	[1]	$ 47
Commodity Contract [Member] | Other Current Liabilities [Member]
Derivative fair values [Abstract]
Derivative Asset, Fair Value, Gross Asset	[1]		927
Derivative Liability, Fair Value, Gross Liability	[1]		1,121
Commodity Contract [Member] | Other Deferred Liabilities and Other [Member]
Derivative fair values [Abstract]
Derivative Asset, Fair Value, Gross Asset	[1]		286
Derivative Liability, Fair Value, Gross Liability	[1]		140
Commodity Contract [Member] | Cash Flow Hedging [Member]
Derivative fair values [Abstract]
Derivative, right to reclaim collateral (receivable)			$ 100
Energy Related Commodity Contract [Member] | Cash Flow Hedging [Member]
Derivatives, Fair Value [Line Items]
Maximum term of derivative hedging contract		4 years
Financial Transmission Rights [Member]
Gross Notional Volume of Open Derivatives [Abstract]
Notional amount, power measure (in MW) | MW		5,159	2,131
Derivative fair values [Abstract]
Derivative Asset, Fair Value, Gross Asset		$ 258	$ 108
Collateral posted against derivative positions		0	0
Financial Transmission Rights [Member] | Other Current Assets/Liabilities
Derivative fair values [Abstract]
Derivative Asset, Fair Value, Gross Asset		258	108
Derivative Liability, Fair Value, Gross Liability		$ 0	$ 0

[1] As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

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Derivative and Hedging Instruments (Details-2) - USD ($) $ in Thousands		Jun. 30, 2025	Dec. 31, 2024
Commodity Contract [Member]
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 1,678	$ 1,213
Gross amounts offset in balance sheet		(1,239)	(1,213)
Collateral posted against derivative positions		0	0
Net amount presented in balance sheet		439	0
Commodity Contract [Member] | Other Current Assets [Member]
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	1,455
Commodity Contract [Member] | Other Noncurrent Assets [Member]
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset	[1]	223
Financial Transmission Rights [Member]
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset		258	108
Gross amounts offset in balance sheet		0	0
Collateral posted against derivative positions		0	0
Net amount presented in balance sheet		258	108
Financial Transmission Rights [Member] | Other Current Assets [Member]
Offsetting Assets [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 258	$ 108

[1] As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

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Derivative and Hedging Instruments (Details-3) - USD ($) $ in Thousands		Jun. 30, 2025	Dec. 31, 2024
Offsetting Liabilities [Line Items]
Collateral posted against derivative positions			$ (100)
Commodity Contract [Member]
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability		$ 1,239	1,261
Gross amounts offset in balance sheet		(1,239)	(1,213)
Collateral posted against derivative positions		0	(48)
Net amount presented in balance sheet		$ 0	0
Commodity Contract [Member] | Other Current Liabilities [Member]
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	[1]		1,121
Commodity Contract [Member] | Other Noncurrent Liabilities [Member]
Offsetting Liabilities [Line Items]
Derivative Liability, Fair Value, Gross Liability	[1]		$ 140

[1] As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

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Derivative and Hedging Instruments (Details-4) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Current and Long-Term Regulatory Asset (Liability)
Derivative Unrealized Realized Gains Losses On Balance Sheet [Line Items]
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Utilities Operating Expense, Purchased Power, Utilities Operating Expense, Cost of Gas Sold	Utilities Operating Expense, Purchased Power, Utilities Operating Expense, Cost of Gas Sold	Utilities Operating Expense, Purchased Power, Utilities Operating Expense, Cost of Gas Sold	Utilities Operating Expense, Purchased Power, Utilities Operating Expense, Cost of Gas Sold
Change In Derivative Fair Value [Roll Forward]
Beginning balance,	$ (1,860)	$ 3,009	$ (60)	$ 5,226
Unrealized loss (gain)	2,118	758	362	2,898
Realized (loss) gain reclassified to a deferred account	(288)	(537)	263	(2,694)
Realized (loss) gain reclassified to income statement	(667)	(1,284)	(1,262)	(3,484)
Ending balance,	$ (697)	$ 1,946	$ (697)	$ 1,946
Other Current Assets
Derivative Unrealized Realized Gains Losses On Balance Sheet [Line Items]
Derivative, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Utilities Operating Expense, Purchased Power, Utilities Operating Expense, Cost of Gas Sold	Utilities Operating Expense, Purchased Power, Utilities Operating Expense, Cost of Gas Sold	Utilities Operating Expense, Purchased Power, Utilities Operating Expense, Cost of Gas Sold	Utilities Operating Expense, Purchased Power, Utilities Operating Expense, Cost of Gas Sold
Change In Derivative Fair Value [Roll Forward]
Beginning balance,	$ 78	$ 275	$ 388	$ 1,569
Unrealized loss (gain)	0	0	0	0
Realized (loss) gain reclassified to a deferred account	288	537	(263)	2,694
Realized (loss) gain reclassified to income statement	30	(285)	271	(3,736)
Ending balance,	$ 396	$ 527	$ 396	$ 527

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Derivative and Hedging Instruments (Details-5) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025 USD ($) Counterparty	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) Counterparty	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Counterparties in net liability position or default [Abstract]
Derivative, net liability position of counterparties	$ 0		$ 0		$ 0
Number of counterparties in default | Counterparty	0		0
Commodity Contract [Member] | Fuel For Electric Generation Purchased Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains) on income statement	$ 198	$ 1,328	$ 596	$ 3,754
Commodity Contract [Member] | Cost Of Gas Sold Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains) on income statement	0	0	(203)	3,265
Financial Transmission Rights [Member] | Fuel For Electric Generation Purchased Power [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains) on income statement	439	241	598	201
Financial Transmission Rights [Member] | Cost Of Gas Sold Expense [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized losses (gains) on income statement	$ 0	$ 0	$ 0	$ 0

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Fair Value of Financial Instruments (Details-1) - USD ($) $ in Thousands		Jun. 30, 2025	Dec. 31, 2024
Liabilities:
Unamortized discount and debt issuance costs, net		$ 4,100	$ 4,400
Carrying Amount [Member]
Liabilities:
Long-term debt	[1]	770,775	773,400
Fair Value [Member]
Liabilities:
Long-term debt	[1]	$ 710,479	$ 698,765

[1] Includes long-term debt due within one year. Excludes debt issuance costs and unamortized discount of $4.1 million and $4.4 million as of June 30, 2025, and December 31, 2024, respectively.

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Fair Value of Financial Instruments (Details-2) - USD ($) $ in Thousands		Jun. 30, 2025	Dec. 31, 2024
Liabilities:
Derivative, right to reclaim collateral			$ 100
Recurring [Member]
Assets:
Derivative assets, net	[1]	$ 1,936	1,321
Liabilities:
Derivative liabilities, net	[1]	1,239	1,261
Deferred compensation		6,753	6,468
Total liabilities		7,992	7,729
Recurring [Member] | Level 1 [Member]
Assets:
Derivative assets, net	[1]	1,416	987
Liabilities:
Derivative liabilities, net	[1]	916	480
Deferred compensation		0	0
Total liabilities		916	480
Recurring [Member] | Level 2 [Member]
Assets:
Derivative assets, net	[1]	0	0
Liabilities:
Derivative liabilities, net	[1]	0	0
Deferred compensation		6,753	6,468
Total liabilities		6,753	6,468
Recurring [Member] | Level 3 [Member]
Assets:
Derivative assets, net	[1]	520	334
Liabilities:
Derivative liabilities, net	[1]	323	781
Deferred compensation		0	0
Total liabilities		$ 323	$ 781

[1] As of June 30, 2025, no collateral was posted against derivative positions. As of December 31, 2024, collateral of less than $0.1 million was posted against and netted with derivative liability positions. The fair value of the derivatives disclosed in this table has not been adjusted for the collateral posted.

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Fair Value of Financial Instruments (Details-3)	6 Months Ended
	Jun. 30, 2025
Deferred compensation plan [Abstract]
Investment interest calculation, investment maturity period (26 weeks)	182 days
Investment interest calculation, monthly compounding rate	1.00%
Investment interest calculation, minimum annual rate compounded monthly	7.00%

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Fair Value of Financial Instruments (Details-4) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning balance,		$ 515	$ (1,726)	$ (447)	$ (2,604)
Realized and unrealized gains (losses):
Included in regulatory assets		0	294	0	1,172
Included in regulatory liability		(318)	0	642	0
Included in earnings	[1]	(665)	(1,330)	(1,262)	(3,855)
Settlements		665	1,330	1,264	3,855
Ending balance,		$ 197	$ (1,432)	$ 197	$ (1,432)

[1] MGE's exchange-traded derivative contracts, over-the-counter party transactions, purchased power agreement, and FTRs are subject to regulatory deferral. These derivatives are therefore marked to fair value and are offset in the financial statements with a corresponding regulatory asset or liability.

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Fair Value of Financial Instruments (Details-5) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Included in earnings	[1]	$ (665)	$ (1,330)	$ (1,262)	$ (3,855)
Fair Value, Net Derivative Asset (Liability), Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]		Utilities Operating Expense, Purchased Power	Utilities Operating Expense, Purchased Power	Utilities Operating Expense, Purchased Power	Utilities Operating Expense, Purchased Power

[1] MGE's exchange-traded derivative contracts, over-the-counter party transactions, purchased power agreement, and FTRs are subject to regulatory deferral. These derivatives are therefore marked to fair value and are offset in the financial statements with a corresponding regulatory asset or liability.

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Joint Plant Ownership (Details) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2025 USD ($) MW	Jun. 30, 2024 USD ($)	Jun. 30, 2025 USD ($) MW	Jun. 30, 2024 USD ($)	Dec. 31, 2024 USD ($)
Jointly Owned Utility Plant Interests [Line Items]
Property, plant, and equipment, net		$ 2,238,086		$ 2,238,086		$ 2,149,138
MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Property, plant, and equipment, net		2,238,114		2,238,114		$ 2,149,165
Paris Units [Member]
Jointly Owned Utility Plant Interests [Line Items]
Projected renewable project costs	[1],[2],[3]	25,000		25,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	[2],[3]	$ 23,400		$ 23,400
Paris Units [Member] | Public Service Commission of Wisconsin [Member]
Allowance for Funds Used During Construction
Authorized AFUDC rate - Signficiant projects (100%)				100.00%
Paris Units [Member] | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, ownership interest	[3]	10.00%		10.00%
Paris Units [Member] | Battery storage | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, plant capacity (in MW) | MW	[3]	11		11
Darien Units [Member]
Jointly Owned Utility Plant Interests [Line Items]
Projected renewable project costs	[1],[2],[4]	$ 63,000		$ 63,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	[2],[4]	$ 46,300		$ 46,300
Darien Units [Member] | Public Service Commission of Wisconsin [Member]
Allowance for Funds Used During Construction
Authorized AFUDC rate - Signficiant projects (100%)				100.00%
Darien Units [Member] | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, ownership interest	[4]	10.00%		10.00%
Darien Units [Member] | Solar | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, plant capacity (in MW) | MW	[4]	25		25
Darien Units [Member] | Battery storage | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, plant capacity (in MW) | MW	[4]	7.5		7.5
Koshkonong Units [Member]
Jointly Owned Utility Plant Interests [Line Items]
Projected renewable project costs	[1],[2],[5]	$ 104,000		$ 104,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	[2],[5]	$ 24,800		$ 24,800
Koshkonong Units [Member] | Public Service Commission of Wisconsin [Member]
Allowance for Funds Used During Construction
Authorized AFUDC rate - Signficiant projects (100%)				100.00%
Koshkonong Units [Member] | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, ownership interest	[5]	10.00%		10.00%
Koshkonong Units [Member] | Solar | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, plant capacity (in MW) | MW	[5]	30		30
Koshkonong Units [Member] | Battery storage | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, plant capacity (in MW) | MW	[5]	16.5		16.5
High Noon [Member]
Jointly Owned Utility Plant Interests [Line Items]
Projected renewable project costs	[2],[6]	$ 99,000		$ 99,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	[2],[6]	$ 17,800		$ 17,800
High Noon [Member] | Public Service Commission of Wisconsin [Member]
Allowance for Funds Used During Construction
Authorized AFUDC rate - Signficiant projects (100%)				100.00%
High Noon [Member] | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, ownership interest	[6]	10.00%		10.00%
High Noon [Member] | Solar | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, plant capacity (in MW) | MW	[6]	30		30
High Noon [Member] | Battery storage | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, plant capacity (in MW) | MW	[6]	16.5		16.5
Columbia Energy Dome [Member]
Jointly Owned Utility Plant Interests [Line Items]
Projected renewable project costs	[2],[7]	$ 17,000		$ 17,000
Public Utilities, Property, Plant and Equipment, Construction Work in Progress	[2],[7]	$ 700		$ 700
Columbia Energy Dome [Member] | Public Service Commission of Wisconsin [Member]
Allowance for Funds Used During Construction
Authorized AFUDC rate - Signficiant projects (100%)				100.00%
Columbia Energy Dome [Member] | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, ownership interest	[7]	19.00%		19.00%
Columbia Energy Dome [Member] | Storage | MGE [Member]
Jointly Owned Utility Plant Interests [Line Items]
Jointly owned utility plant, plant capacity (in MW) | MW	[7]	3		3
Paris, Darien, Koshkonong, High Noon, and Columbia Energy Dome Units [Member]
Allowance for Funds Used During Construction
AFUDC		$ 500	$ 1,500	$ 2,100	$ 2,700

[1] Estimated costs are expected to exceed PSCW previously approved Certificate of Authority (CA) levels. Notifications are provided to the PSCW when costs increase above CA levels. MGE has and will continue to request recovery of the updates in its rate case proceedings.

[2] Excluding AFUDC.

[3] Paris Solar-Battery Park is located in the Town of Paris in Kenosha County, Wisconsin.

[4] Darien Solar Energy Center is located in Walworth and Rock Counties in southern Wisconsin.

[5] Koshkonong Solar Energy Center is located in the Towns of Christiana and Deerfield in Dane County, Wisconsin.

[6] High Noon Solar Project is located in Columbia County, Wisconsin.

[7] Columbia Energy Dome is located in Columbia County, Wisconsin.

XML

Revenue (Details-1) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Total Operating Revenue [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	$ 159,452	$ 145,713	$ 378,422	$ 337,049
Electric [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	129,313	120,383	254,767	236,508
Electric [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	43,182	40,321	88,321	81,462
Electric [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	64,027	64,161	124,662	124,024
Electric [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	3,117	3,445	6,081	6,855
Electric [Member] | Other-retail/municipal
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	10,342	10,403	19,690	20,093
Electric [Member] | Total Retail [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	120,668	118,330	238,754	232,434
Electric [Member] | Sales To The Market [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	7,840	1,519	14,320	2,595
Electric [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	805	534	1,693	1,479
Gas [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	29,925	25,116	123,406	100,285
Gas [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	17,956	15,589	71,824	58,987
Gas [Member] | Commercial/Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	10,434	7,876	47,547	37,400
Gas [Member] | Total Retail [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	28,390	23,465	119,371	96,387
Gas [Member] | Gas Transportation [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	1,384	1,505	3,697	3,585
Gas [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	151	146	338	313
Non Regulated Energy [Member]
Disaggregation of Revenue [Line Items]
Revenues recognized from contracts with customers	$ 214	$ 214	$ 249	$ 256

XML

Segment Information (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Segment Reporting Information [Line Items]
Operating revenues		$ 159,452	$ 145,713	$ 378,422	$ 337,049
Depreciation and amortization		(28,354)	(26,932)	(56,032)	(53,532)
Income tax (provision) benefit		(2,975)	(1,472)	(9,271)	(4,280)
Equity in earnings of investment				6,241	5,526
Net Income (Loss)		26,498	23,794	68,090	57,608
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				111,753	111,622
Electric [Member]
Segment Reporting Information [Line Items]
Operating revenues		129,313	120,383	254,767	236,508
Gas [Member]
Segment Reporting Information [Line Items]
Operating revenues		29,925	25,116	123,406	100,285
Non Regulated Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues		214	214	249	256
Transmission Investment [Member]
Segment Reporting Information [Line Items]
Operating revenues		0	0	0	0
All Others [Member]
Segment Reporting Information [Line Items]
Operating revenues		0	0	0	0
Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues		159,452	145,713	378,422	337,049
Fuel and purchased power		(21,854)	(20,087)	(43,801)	(42,233)
Purchased gas costs		(11,313)	(6,293)	(65,277)	(48,170)
Depreciation and amortization		(28,354)	(26,932)	(56,032)	(53,532)
Interest expense		(9,142)	(8,989)	(18,304)	(18,001)
Other segment items	[1]	(62,376)	(60,926)	(123,888)	(118,751)
Income tax (provision) benefit		(2,975)	(1,472)	(9,271)	(4,280)
Equity in earnings of investment		3,060	2,780	6,241	5,526
Net Income (Loss)		26,498	23,794	68,090	57,608
Operating Segments [Member] | Electric [Member]
Segment Reporting Information [Line Items]
Operating revenues		129,285	120,328	254,691	236,399
Fuel and purchased power		(22,524)	(20,840)	(45,630)	(43,910)
Purchased gas costs		0	0	0	0
Depreciation and amortization		(22,094)	(20,888)	(43,629)	(41,538)
Interest expense		(6,485)	(6,323)	(12,978)	(12,651)
Other segment items	[1]	(58,130)	(57,257)	(114,109)	(110,802)
Income tax (provision) benefit		(472)	641	1,430	3,926
Equity in earnings of investment		0	0	0	0
Net Income (Loss)		19,580	15,661	39,775	31,424
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				83,034	86,755
Operating Segments [Member] | Gas [Member]
Segment Reporting Information [Line Items]
Operating revenues		32,483	27,288	132,436	107,668
Fuel and purchased power		0	0	0	0
Purchased gas costs		(13,211)	(7,720)	(72,501)	(53,893)
Depreciation and amortization		(4,347)	(4,163)	(8,579)	(8,245)
Interest expense		(1,768)	(1,709)	(3,531)	(3,419)
Other segment items	[1]	(15,015)	(14,456)	(31,111)	(29,161)
Income tax (provision) benefit		561	810	(4,426)	(2,286)
Equity in earnings of investment		0	0	0	0
Net Income (Loss)		(1,297)	50	12,288	10,664
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				22,975	20,879
Operating Segments [Member] | Non Regulated Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues		11,335	11,160	22,474	22,029
Fuel and purchased power		0	0	0	0
Purchased gas costs		0	0	0	0
Depreciation and amortization		(1,913)	(1,881)	(3,824)	(3,749)
Interest expense		(889)	(957)	(1,795)	(1,931)
Other segment items	[1]	(23)	(17)	(67)	(41)
Income tax (provision) benefit		(2,318)	(2,262)	(4,573)	(4,442)
Equity in earnings of investment		0	0	0	0
Net Income (Loss)		6,192	6,043	12,215	11,866
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				5,744	3,988
Operating Segments [Member] | Transmission Investment [Member]
Segment Reporting Information [Line Items]
Operating revenues		0	0	0	0
Fuel and purchased power		0	0	0	0
Purchased gas costs		0	0	0	0
Depreciation and amortization		0	0	0	0
Interest expense		0	0	0	0
Other segment items	[1]	0	0	0	(2)
Income tax (provision) benefit		(835)	(758)	(1,702)	(1,506)
Equity in earnings of investment		3,060	2,780	6,241	5,526
Net Income (Loss)		2,225	2,022	4,539	4,018
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				0	0
Operating Segments [Member] | Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues		173,103	158,776	409,601	366,096
Fuel and purchased power		(22,524)	(20,840)	(45,630)	(43,910)
Purchased gas costs		(13,211)	(7,720)	(72,501)	(53,893)
Depreciation and amortization		(28,354)	(26,932)	(56,032)	(53,532)
Interest expense		(9,142)	(8,989)	(18,304)	(18,001)
Other segment items	[1]	(73,168)	(71,730)	(145,287)	(140,006)
Income tax (provision) benefit		(3,064)	(1,569)	(9,271)	(4,308)
Equity in earnings of investment		3,060	2,780	6,241	5,526
Net Income (Loss)		26,700	23,776	68,817	57,972
Operating Segments [Member] | All Others [Member]
Segment Reporting Information [Line Items]
Operating revenues		0	0	0	0
Fuel and purchased power		0	0	0	0
Purchased gas costs		0	0	0	0
Depreciation and amortization		0	0	0	0
Interest expense		0	0	0	0
Other segment items	[1]	(291)	(79)	(727)	(392)
Income tax (provision) benefit		89	97	0	28
Equity in earnings of investment		0	0	0	0
Net Income (Loss)		(202)	18	(727)	(364)
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				0	0
Consolidation Elimination Entries [Member]
Segment Reporting Information [Line Items]
Operating revenues		(13,651)	(13,063)	(31,179)	(29,047)
Fuel and purchased power		670	753	1,829	1,677
Purchased gas costs		1,898	1,427	7,224	5,723
Depreciation and amortization		0	0	0	0
Interest expense		0	0	0	0
Other segment items	[1]	11,083	10,883	22,126	21,647
Income tax (provision) benefit		0	0	0	0
Equity in earnings of investment		0	0	0	0
Net Income (Loss)		0	0	0	0
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				0	0
Consolidation Elimination Entries [Member] | Electric [Member]
Segment Reporting Information [Line Items]
Operating revenues		(28)	(55)	(76)	(109)
Consolidation Elimination Entries [Member] | Gas [Member]
Segment Reporting Information [Line Items]
Operating revenues		2,558	2,172	9,030	7,383
Consolidation Elimination Entries [Member] | Non Regulated Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues		11,121	10,946	22,225	21,773
Consolidation Elimination Entries [Member] | Transmission Investment [Member]
Segment Reporting Information [Line Items]
Operating revenues		0	0	0	0
Consolidation Elimination Entries [Member] | Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues		13,651	13,063	31,179	29,047
Consolidation Elimination Entries [Member] | All Others [Member]
Segment Reporting Information [Line Items]
Operating revenues		0	0	0	0
MGE [Member]
Segment Reporting Information [Line Items]
Operating revenues		159,452	145,713	378,422	337,049
Depreciation and amortization		(28,354)	(26,932)	(56,032)	(53,532)
Income tax (provision) benefit		(2,229)	(811)	(7,569)	(2,802)
Net Income (Loss) Attributable to Noncontrolling Interest		5,714	5,766	11,313	11,363
Net Income (Loss)		18,761	15,988	52,965	42,591
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				111,753	111,622
MGE [Member] | Electric [Member]
Segment Reporting Information [Line Items]
Operating revenues		129,313	120,383	254,767	236,508
MGE [Member] | Gas [Member]
Segment Reporting Information [Line Items]
Operating revenues		29,925	25,116	123,406	100,285
MGE [Member] | Non Regulated Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues		214	214	249	256
MGE [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues		159,452	145,713	378,422	337,049
Fuel and purchased power		(21,854)	(20,087)	(43,801)	(42,233)
Purchased gas costs		(11,313)	(6,293)	(65,277)	(48,170)
Depreciation and amortization		(28,354)	(26,932)	(56,032)	(53,532)
Interest expense		(9,142)	(8,989)	(18,304)	(18,001)
Other segment items	[2]	(62,085)	(60,847)	(123,161)	(118,357)
Income tax (provision) benefit		(2,229)	(811)	(7,569)	(2,802)
Net Income (Loss) Attributable to Noncontrolling Interest		(5,714)	(5,766)	(11,313)	(11,363)
Net Income (Loss)		18,761	15,988	52,965	42,591
MGE [Member] | Operating Segments [Member] | Electric [Member]
Segment Reporting Information [Line Items]
Operating revenues		129,285	120,328	254,691	236,399
Fuel and purchased power		(22,524)	(20,840)	(45,630)	(43,910)
Purchased gas costs		0	0	0	0
Depreciation and amortization		(22,094)	(20,888)	(43,629)	(41,538)
Interest expense		(6,485)	(6,323)	(12,978)	(12,651)
Other segment items	[2]	(58,130)	(57,257)	(114,109)	(110,802)
Income tax (provision) benefit		(472)	641	1,430	3,926
Net Income (Loss) Attributable to Noncontrolling Interest		0	0	0	0
Net Income (Loss)		19,580	15,661	39,775	31,424
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				83,034	86,755
MGE [Member] | Operating Segments [Member] | Gas [Member]
Segment Reporting Information [Line Items]
Operating revenues		32,483	27,288	132,436	107,668
Fuel and purchased power		0	0	0	0
Purchased gas costs		(13,211)	(7,720)	(72,501)	(53,893)
Depreciation and amortization		(4,347)	(4,163)	(8,579)	(8,245)
Interest expense		(1,768)	(1,709)	(3,531)	(3,419)
Other segment items	[2]	(15,015)	(14,456)	(31,111)	(29,161)
Income tax (provision) benefit		561	810	(4,426)	(2,286)
Net Income (Loss) Attributable to Noncontrolling Interest		0	0	0	0
Net Income (Loss)		(1,297)	50	12,288	10,664
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				22,975	20,879
MGE [Member] | Operating Segments [Member] | Non Regulated Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues		11,335	11,160	22,474	22,029
Fuel and purchased power		0	0	0	0
Purchased gas costs		0	0	0	0
Depreciation and amortization		(1,913)	(1,881)	(3,824)	(3,749)
Interest expense		(889)	(957)	(1,795)	(1,931)
Other segment items	[2]	(23)	(17)	(67)	(41)
Income tax (provision) benefit		(2,318)	(2,262)	(4,573)	(4,442)
Net Income (Loss) Attributable to Noncontrolling Interest		0	0	0	0
Net Income (Loss)		6,192	6,043	12,215	11,866
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				5,744	3,988
MGE [Member] | Operating Segments [Member] | Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues		173,103	158,776	409,601	366,096
Fuel and purchased power		(22,524)	(20,840)	(45,630)	(43,910)
Purchased gas costs		(13,211)	(7,720)	(72,501)	(53,893)
Depreciation and amortization		(28,354)	(26,932)	(56,032)	(53,532)
Interest expense		(9,142)	(8,989)	(18,304)	(18,001)
Other segment items	[2]	(73,168)	(71,730)	(145,287)	(140,004)
Income tax (provision) benefit		(2,229)	(811)	(7,569)	(2,802)
Net Income (Loss) Attributable to Noncontrolling Interest		0	0	0	0
Net Income (Loss)		24,475	21,754	64,278	53,954
MGE [Member] | Consolidation Elimination Entries [Member]
Segment Reporting Information [Line Items]
Operating revenues		(13,651)	(13,063)	(31,179)	(29,047)
Fuel and purchased power		670	753	1,829	1,677
Purchased gas costs		1,898	1,427	7,224	5,723
Depreciation and amortization		0	0	0	0
Interest expense		0	0	0	0
Other segment items	[2]	11,083	10,883	22,126	21,647
Income tax (provision) benefit		0	0	0	0
Net Income (Loss) Attributable to Noncontrolling Interest		(5,714)	(5,766)	(11,313)	(11,363)
Net Income (Loss)		(5,714)	(5,766)	(11,313)	(11,363)
Segment Reporting Information Assets And Capital Expenditures [Abstract]
Segment, Expenditure, Addition to Long-Lived Assets				0	0
MGE [Member] | Consolidation Elimination Entries [Member] | Electric [Member]
Segment Reporting Information [Line Items]
Operating revenues		(28)	(55)	(76)	(109)
MGE [Member] | Consolidation Elimination Entries [Member] | Gas [Member]
Segment Reporting Information [Line Items]
Operating revenues		2,558	2,172	9,030	7,383
MGE [Member] | Consolidation Elimination Entries [Member] | Non Regulated Energy [Member]
Segment Reporting Information [Line Items]
Operating revenues		11,121	10,946	22,225	21,773
MGE [Member] | Consolidation Elimination Entries [Member] | Total Reportable Segments
Segment Reporting Information [Line Items]
Operating revenues		$ 13,651	$ 13,063	$ 31,179	$ 29,047

[1] Other segment items include AFUDC Income, Other Income, Net, Other Operations and Maintenance, Other General Taxes, and Interest Revenue.

[2] Other segment items include AFUDC Income, Other Income, Net, Other Operations and Maintenance, Other General Taxes, and Interest Revenue.