ALLIANT ENERGY CORP

For the period ended Dec 31, 2025. Filed Feb 20, 2026.

About this filing

A company's yearly report to the SEC, with audited financial statements. It is the fullest account a company gives of its business, its finances and the risks it sees.

FY2025 · Filed Feb 20, 2026

LNT$72.67-1.0%Stored close · as of Nov 6, 2026

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Contents

	Page Number
Definitions	1
Forward-looking Statements	1
Website Access to Reports	4
Part I.	Item 1. Business	4
	Item 1A. Risk Factors	16
	Item 1B. Unresolved Staff Comments	23
	Item 1C. Cybersecurity	23
	Item 2. Properties	25
	Item 3. Legal Proceedings	27
	Item 4. Mine Safety Disclosures	27
	Information About Executive Officers	27
Part II.	Item 5. Market for Registrants’ Common Equity, Related Stockholder Matters and Issuer Purchases of Equity Securities	28
	Item 6. [Reserved]	28
	Item 7. Management’s Discussion and Analysis of Financial Condition and Results of Operations	28
	Item 7A. Quantitative and Qualitative Disclosures About Market Risk	48
	Item 8. Financial Statements and Supplementary Data	48
		Alliant Energy Corporation	49
		Interstate Power and Light Company	55
		Wisconsin Power and Light Company	61
		Combined Notes to Consolidated Financial Statements	67
			1. Summary of Significant Accounting Policies	67
			2. Regulatory Matters	73
			3. Property, Plant and Equipment	76
			4. Jointly-owned Electric Utility Plant	77
			5. Receivables	77
			6. Investments	78
			7. Common Equity	79
			8. Debt	80
			9. Leases	84
			10. Revenues	85
			11. Income Taxes	86
			12. Benefit Plans	89
			13. Asset Retirement Obligations	97
			14. Derivative Instruments	97
			15. Fair Value Measurements	99
			16. Commitments and Contingencies	101
			17. Segments of Business	103
			18. Related Parties	106
	Item 9. Changes in and Disagreements With Accountants on Accounting and Financial Disclosure	106
	Item 9A. Controls and Procedures	106
	Item 9B. Other Information	109
	Item 9C. Disclosure Regarding Foreign Jurisdictions that Prevent Inspections	109
Part III.	Item 10. Directors, Executive Officers and Corporate Governance	109
	Item 11. Executive Compensation	109
	Item 12. Security Ownership of Certain Beneficial Owners and Management and Related Stockholder Matters	109
	Item 13. Certain Relationships and Related Transactions, and Director Independence	110
	Item 14. Principal Accounting Fees and Services	110
Part IV.	Item 15. Exhibits, Financial Statement Schedules	110
Signatures	116

ContentsView on SEC.gov

The text of this filing, as the company filed it with the SEC, without its images or exhibits. This is not investment advice.

About this filing

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