CONTROLS AND PROCEDURES
−Removed: Alliant Energy’s, IPL’s and WPL’s management evaluated, with the participation of each of Alliant Energy’s, IPL’s and WPL’s Chief Executive Officer, Chief Financial Officer and Disclosure Committee, the effectiveness of the design and operation of Alliant Energy’s, IPL’s and WPL’s disclosure controls and procedures as of the end of the quarter ended December 31, 2024 pursuant to the requirements of the Securities Exchange Act of 1934, as amended.
−Removed: Based on their evaluation, the Chief Executive Officer and the Chief Financial Officer concluded that Alliant Energy’s, IPL’s and WPL’s disclosure controls and procedures were effective as of the end of the quarter ended December 31, 2024.
−Removed: There was no change in Alliant Energy’s, IPL’s and WPL’s internal control over financial reporting that occurred during the quarter ended December 31, 2024 that has materially affected, or is reasonably likely to materially affect, Alliant Energy’s, IPL’s and WPL’s internal control over financial reporting.
+Added: Alliant Energy’s, IPL’s and WPL’s management evaluated, with the participation of each of Alliant Energy’s, IPL’s and WPL’s Chief Executive Officer, Chief Financial Officer and Disclosure Committee, the effectiveness of the design and operation of Alliant Energy’s, IPL’s and WPL’s disclosure controls and procedures (as defined in Rule 13a-15(e) of the Securities Exchange Act of 1934, as amended) as of December 31, 2025 pursuant to the requirements of the Securities Exchange Act of 1934, as amended.
+Added: Based on their evaluation, the Chief Executive Officer and the Chief Financial Officer concluded that Alliant Energy’s, IPL’s and WPL’s disclosure controls and procedures were effective as of the quarter ended December 31, 2025.
+Added: There was no change in Alliant Energy’s, IPL’s and WPL’s internal control over financial reporting that occurred during the quarter ended December 31, 2025 that has materially affected, or is reasonably likely to materially affect, Alliant Energy’s, IPL’s or WPL’s internal control over financial reporting.
Management’s Annual Report on Internal Control over Financial Reporting - The management of Alliant Energy, IPL and WPL are responsible for establishing and maintaining adequate internal control over financial reporting, as such term is defined in Rules 13a-15(f) and 15d-15(f) under the Securities Exchange Act of 1934, as amended.
7 unchanged sentences
This report does not include an attestation report of IPL’s and WPL’s independent registered public accounting firm regarding its assessment of IPL’s and WPL’s internal control over financial reporting.
−Removed: Table of C o ntents
REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM
23 unchanged sentences
February 20, 2026
−Removed: Table of C o ntents
OTHER INFORMATION
2 unchanged sentences
DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE
−Removed: The directors of Alliant Energy, IPL and WPL are the same, and therefore, the information required by Item 10 relating to directors and nominees for election of directors is the same for all registrants.
−Removed: The information required by Item 10 relating to directors and nominees for election of directors at the 2025 Annual Meeting of Shareowners, the timely filing of reports under Section 16 of the Securities Exchange Act of 1934, audit committees and audit committee financial experts, insider trading policies and procedures, and Alliant Energy’s, IPL’s and WPL’s Code of Conduct is incorporated herein by reference to the relevant information in the 2025 Alliant Energy Proxy Statement, which will be filed with the SEC within 120 days after the end of Alliant Energy’s, IPL’s and WPL’s fiscal years.
−Removed: The code of ethics, also referred to as the Code of Conduct, of Alliant Energy, IPL and WPL are the same.
−Removed: Information regarding executive officers of Alliant Energy, IPL and WPL may be found in Part I of this report under the caption “ Information About Executive Officers .”
+Added: The information required by Item 10 relating to directors and nominees for election of directors at the 2026 Annual Meeting of Shareowners, the timely filing of reports under Section 16 of the Securities Exchange Act of 1934, audit committees and audit committee financial experts, insider trading policies and procedures, and Alliant Energy’s Code of Conduct is incorporated herein by reference to the relevant information in the 2026 Alliant Energy Proxy Statement, which will be filed with the SEC within 120 days after the end of Alliant Energy’s fiscal year.
+Added: Information regarding executive officers of Alliant Energy may be found in Part I of this report under the caption “ Information About Executive Officers .”
+Added: IPL and WPL are omitted pursuant to Instruction I(2)(c).
EXECUTIVE COMPENSATION
−Removed: The directors and executive officers of Alliant Energy, IPL and WPL for which compensation information must be included are the same.
−Removed: Therefore, the information required by Item 11 for each of Alliant Energy, IPL and WPL is incorporated herein by reference to the relevant information in the 2025 Alliant Energy Proxy Statement, which will be filed with the SEC within 120 days after the end of Alliant Energy’s, IPL’s and WPL’s fiscal years.
+Added: The information required by Item 11 for Alliant Energy is incorporated herein by reference to the relevant information in the 2026 Alliant Energy Proxy Statement, which will be filed with the SEC within 120 days after the end of Alliant Energy’s fiscal year.
+Added: IPL and WPL are omitted pursuant to Instruction I(2)(c).
SECURITY OWNERSHIP OF CERTAIN BENEFICIAL OWNERS AND MANAGEMENT AND RELATED STOCKHOLDER MATTERS
4 unchanged sentences
Plan Category warrants and rights warrants and rights securities reflected in column (A))
−Removed: Equity compensation plans approved by shareowners 1,529,346 (a) $51.63 7,107,084 (b)
−Removed: Equity compensation plans not approved by shareowners (c) N/A N/A N/A (d)
−Removed: 1,529,346 $51.63 7,107,084
+Added: Equity compensation plans approved by shareowners 1,686,388 (a) N/A (b) 6,785,563 (c)
+Added: Equity compensation plans not approved by shareowners (d) N/A N/A N/A (e)
+Added: 1,686,388 N/A 6,785,563
(a) Represents performance shares and restricted stock units granted under the 2020 OIP, all of which are paid out in shares of Alliant Energy’s common stock.
1 unchanged sentence
The restricted stock units vest at the expiration of a three-year time-vesting period.
−Removed: (b) All of the available shares under the 2020 OIP may be issued as awards in the form of shares of Alliant Energy’s common stock, restricted stock, restricted stock units, performance shares, performance units and other stock-based or cash-based awards.
+Added: (b) No cash consideration is received when shares are distributed for earned performance shares and restricted stock units.
+Added: Accordingly, there is no weighted-average exercise price.
+Added: (c) All of the available shares under the 2020 OIP may be issued as awards in the form of shares of Alliant Energy’s common stock, restricted stock, restricted stock units, performance shares, performance units and other stock-based or cash-based awards.
As of December 31, 2025, there were performance shares and restricted stock units outstanding under the 2020 OIP, the only plan under which such equity awards are currently granted.
−Removed: (c) As of December 31, 2024, there were 372,116 shares of Alliant Energy’s common stock held under the DCP, which is described in Note 1 2 (c) .
−Removed: (d) There is no limit on the number of shares of Alliant Energy’s common stock that may be held under the DCP.
−Removed: The remainder of the information required by Item 12 for Alliant Energy, and the information required by Item 12 for each of IPL and WPL, is incorporated herein by reference to the relevant information in the 2025 Alliant Energy Proxy Statement, which will be filed with the SEC within 120 days after the end of Alliant Energy’s, IPL’s and WPL’s fiscal year.
−Removed: Table of C o ntents
+Added: (d) As of December 31, 2025, there were 367,338 shares of Alliant Energy’s common stock held under the DCP, which is described in Note 1 2 (c) .
+Added: (e) There is no limit on the number of shares of Alliant Energy’s common stock that may be held under the DCP.
+Added: The remainder of the information required by Item 12 for Alliant Energy is incorporated herein by reference to the relevant information in the 2026 Alliant Energy Proxy Statement, which will be filed with the SEC within 120 days after the end of Alliant Energy’s fiscal year.
+Added: IPL and WPL are omitted pursuant to Instruction I(2)(c).
CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE
−Removed: The information required by Item 13 for each of Alliant Energy, IPL and WPL is incorporated herein by reference to the relevant information in the 2025 Alliant Energy Proxy Statement, which will be filed with the SEC within 120 days after the end of Alliant Energy’s, IPL’s and WPL’s fiscal years.
+Added: The information required by Item 13 for Alliant Energy is incorporated herein by reference to the relevant information in the 2026 Alliant Energy Proxy Statement, which will be filed with the SEC within 120 days after the end of Alliant Energy’s fiscal year.
+Added: IPL and WPL are omitted pursuant to Instruction I(2)(c).
PRINCIPAL ACCOUNTING FEES AND SERVICES
15 unchanged sentences
IPL’s and WPL’s audit fees also included their respective portion of fees for the 2025 and 2024 audits of Alliant Energy’s financial statements and effectiveness of internal controls over financial reporting.
−Removed: IPL’s and WPL’s audit-related fees for 2024 and 2023 consisted of the fees billed for services rendered related to employee benefits plan audits and other attest services.
−Removed: IPL’s and WPL’s tax fees for 2024 consisted of the fees billed for professional services rendered for tax compliance, and 2023 consisted of the fees billed for professional services rendered for tax compliance, tax advice and tax planning, including all services performed by the tax professional staff of affiliates of the independent registered public accounting firm, except those rendered in connection with the audit.
+Added: IPL’s and WPL’s audit-related fees for 2025 and 2024 consisted of the fees billed for services rendered related to employee benefits plan audits, other attest services and WPL’s audit-related fees for 2025 also included an audit of expenditures of federal awards for the Department of Energy.
+Added: IPL’s and WPL’s tax fees for 2025 and 2024 consisted of the fees billed for professional services rendered for tax compliance.
All other fees for 2025 and 2024 for IPL and WPL consisted of license fees for accounting research software products and seminars.
2 unchanged sentences
(1) Consolidated Financial Statements - Refer to Item 8 Financial Statements and Supplementary Data for Alliant Energy’s, IPL’s and WPL’s financial statements and Reports of Independent Registered Public Accounting Firm (Public Company Accounting Oversight Board ID No.
−Removed: Table of C o ntents
(2) Financial Statement Schedules -
8 unchanged sentences
Interest expense 57 40 34
+Added: Other ( 3 ) 5 4
Total other (income) and deductions ( 809 ) ( 689 ) ( 704 )
Income before income taxes 805 686 701
−Removed: Income tax expense (benefit) ( 3 ) ( 5 ) 2
+Added: Income tax benefit ( 6 ) ( 3 ) ( 5 )
Net income $ 811 $ 689 $ 706
4 unchanged sentences
Current assets:
+Added: Cash and cash equivalents $ 512 $ —
Notes receivable from affiliated companies 114 103
21 unchanged sentences
Refer to accompanying Notes to Condensed Financial Statements.
−Removed: Table of C o ntents
ALLIANT ENERGY CORPORATION (Parent Company Only) Year Ended December 31,
20 unchanged sentences
Income taxes, net:
+Added: Federal $ 4 $ 11 $ 8
+Added: State - Iowa — ( 15 ) ( 13 )
+Added: State - Wisconsin — 12 27
+Added: Total income taxes, net $ 4 $ 8 $ 22
Refer to accompanying Notes to Condensed Financial Statements.
4 unchanged sentences
In the Condensed Financial Statements of Alliant Energy Corporation (Parent Company Only), investments in subsidiaries are accounted for using the equity method.
−Removed: SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES
−Removed: Balance, (Charged to Balance,
−Removed: Description January 1 Expense) Deductions (a) December 31
−Removed: (in millions)
−Removed: Valuation and Qualifying Accounts Which are Deducted in the Balance Sheet from the Assets to Which They Apply:
−Removed: Accumulated Provision for Uncollectible Accounts:
−Removed: Alliant Energy (b)
−Removed: Year ended December 31, 2024 $ 8 $ 24 $ 24 $ 8
−Removed: Year ended December 31, 2023 7 20 19 8
−Removed: Year ended December 31, 2022 11 17 21 7
−Removed: Year ended December 31, 2024 $ — $ 13 $ 13 $ —
−Removed: Year ended December 31, 2023 — 11 11 —
−Removed: Year ended December 31, 2022 1 7 8 —
−Removed: Year ended December 31, 2024 $ 8 $ 11 $ 11 $ 8
−Removed: Year ended December 31, 2023 7 9 8 8
−Removed: Year ended December 31, 2022 10 10 13 7
−Removed: The above provisions relate to various customer, notes and other receivable balances included in various line items on the respective balance sheets.
−Removed: Table of C o ntents
−Removed: (a) Deductions are of the nature for which the reserves were created.
−Removed: In the case of the accumulated provision for uncollectible accounts, deductions from this reserve are reduced by recoveries of amounts previously written off.
−Removed: (b) Refer to Note 5(b) for discussion of IPL’s sales of accounts receivable program.
All other schedules are omitted because they are not applicable or not required, or because that required information is shown either in the financial statements or in the notes thereto.
8 unchanged sentences
3.4 Amended and Restated Bylaws of WPL, effective October 27, 2020 (incorporated by reference to Exhibit 3.3 to WPL’s Form 8-K, filed October 29, 2020 (File No.
+Added: Exhibit Number Description
3.5 Amended and Restated Articles of Incorporation of IPL, effective December 20, 2021 (incorporated by reference to Exhibit 3.1 to IPL’s Form 8-K, filed December 21, 2021 (File No.
3 unchanged sentences
4.1b Second Amendment to Amended and Restated Five-Year Master Credit Agreement, effective December 18, 2024, among Alliant Energy, IPL, WPL, Wells Fargo Bank, N atio nal A s sociation and the lender parties set forth therein (incorporated by reference to Exhibit 4.1 to Alliant Energy’s Form 8-K filed December 18, 2024 (File No.
+Added: 4.1c Extension and Third Amendment to Amended and Restated Five-Year Master Credit Agreement, effective December 18, 2025, among Alliant Energy, IPL, WPL, Wells Fargo Bank, National Association and the lender parties set forth therein
4.2 Indenture, dated as of March 2, 2023, between Alliant Energy and The Bank of New York Mellon Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.1 to Alliant Energy's Form 8-K, filed March 3, 2023 (File No.
+Added: 4.3 Indenture, dated as of May 15, 2025, between Alliant Energy and The Bank of New York Mellon Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.1 to Alliant Energy’s Form 8-K, filed May 15, 2025 (File No.
+Added: 4.4 Indenture, dated as of September 26, 2025, between Alliant Energy and The Bank of New York Mellon Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.1 to Alliant Energy’s Form 8-K, filed September 26, 2025 (File No.
+Added: 4.4a First Supplemental Indenture, dated as of September 26, 2025, between Alliant Energy and The Bank of New York Mellon Trust Company, N.A., as trustee, relating to the 5.750% Fixed-to-Fixed Reset Rate Junior Subordinated Notes due 2056 (incorporated by reference to Exhibit 4.2 to Alliant Energy’s Form 8-K, filed September 26, 2025 (File No.
4.5 Indenture, dated as of June 12, 2018, among AEF, Alliant Energy, as guarantor, and The Bank of New York Mellon Trust Company, N.A., as trustee (incorporated by reference to Exhibit 4.1 to Alliant Energy’s Form 8-K, filed June 12, 2018 (File No.
4 unchanged sentences
4.10 Indenture, dated as of June 20, 1997, between WPL and U.S.
−Removed: Bank Trust Comp any , N .
−Removed: , Successor, as Trustee (incorporated by reference to Exhibit 4.33 to Amendment No.
+Added: Bank Trust Company, N.
+Added: A., Successor, as Trustee (incorporated by reference to Exhibit 4.33 to Amendment No.
2 to WPL’s Registration Statement on Form S-3 (Reg.
−Removed: 4.8a First Supplemental Indenture, dated September 16, 2021, among WPL, Wells Fargo Bank, N ational A ssociation , as Original Trustee, and U.S.
−Removed: Bank N ational A ssociation , as Series Trustee (incorporated by reference to Exhibit 4.1 to WPL's Form 8-K, filed September 16, 2021 (File No.
+Added: 4.10a First Supplemental Indenture, dated September 16, 2021, among WPL, Wells Fargo Bank, National Association, as Original Trustee, and U.S.
+Added: Bank National Association, as Series Trustee (incorporated by reference to Exhibit 4.1 to WPL's Form 8-K, filed September 16, 2021 (File No.
4.11 Officers’ Certificate, dated as of July 28, 2004, creating WPL’s 6.25% Debentures due July 31, 2034 (incorporated by reference to Exhibit 4.1 to WPL’s Form 8-K, filed August 2, 2004 (File No.
2 unchanged sentences
4.14 Officers’ Certificate, dated as of October 14, 2014, creating WPL’s 4.10% Debentures due October 15, 2044 (incorporated by reference to Exhibit 4.1 to WPL’s Form 8-K, filed October 14, 2014 (File No.
−Removed: Table of C o ntents
−Removed: Exhibit Number Description
4.15 Officers’ Certificate, dated as of October 10, 2017, creating WPL’s 3.05% Debentures due October 15, 2027 (incorporated by reference to Exhibit 4.1 to WPL’s Form 8-K, filed October 10, 2017 (File No.
4 unchanged sentences
4.20 Officers’ Certificate, dated as of March 7, 2024, creating WPL’s 5.375% Debentures due March 30, 2034 (incorporated by reference to Exhibit 4.1 to WPL’s Form 8-K, filed March 7, 2024 (File No.
+Added: Exhibit Number Description
+Added: 4.21 Officers’ Certificate, dated December 5, 2025, creating WPL’s 5.700% Debentures due 2055 (incorporated by reference to Exhibit 4.1 to WPL’s Form 8-K, filed December 5, 2025 (File No.
4.22 Indenture (For Senior Unsecured Debt Securities), dated as of August 20, 2003, between IPL and The Bank of New York Mellon Trust Co., N.A.
4 unchanged sentences
4.25 Officer’s Certificate, dated as of July 7, 2009, creating IPL’s 6.25% Senior Debentures due July 15, 2039 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed July 8, 2009 (File No.
−Removed: 4.23 Officer’s Certificate, dated as of July 7, 2009, creating IPL’s 6.25% Senior Debentures due July 15, 2039 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed July 8, 2009 (File No.
4.26 Officer’s Certificate, dated as of October 8, 2013, creating IPL’s 4.70% Senior Debentures due October 15, 2043 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed October 8, 2013 (File No.
−Removed: 4.25 Officer’s Certificate, dated as of August 18, 2015, creating IPL’s 3.40% Senior Debentures due August 15, 2025 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed August 18, 2015 (File No.
4.27 Officer’s Certificate, dated as of September 15, 2016, creating IPL’s 3.70% Senior Debentures due September 15, 2046 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed September 15, 2016 (File No.
6 unchanged sentences
4.34 Officer’s Certificate, dated as of September 6, 2024, creating IPL’s 4.950% Senior Debentures due September 30, 2034 and IPL’s 5.450% Senior Debentures due September 30, 2054 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed September 6, 2024 (File No.
+Added: 4.35 Officer’s Certificate, dated as of May 19, 2025, creating IPL’s 5.600% Senior Debentures due June 29, 2035 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed May 19, 2025 (File No.
+Added: 4.36 Officer’s Certificate, dated as of September 11, 2025, creating IPL’s 5.600% Senior Debentures due October 1, 2055 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed September 11, 2025 (File No.
4.37 Description of Common Stock of Alliant Energy (incorporated by reference to Exhibit 4.32 to Alliant Energy ’ s Form 10-K for the year 2023 (File No.
−Removed: 10.1 Amended and Restated Term Loan Credit Agreement, dated as of March 1, 2024, among AEF, Alliant Energy, U.S.
+Added: 10.1 Second Amended and Restated Term Loan Credit Agreement, dated as of March 3, 2025, among AEF, Alliant Energy, U.S.
Bank National Association and the lender parties set forth therein (incorporated by reference to Exhibit 10.1 to Alliant Energy’s Form 8-K, filed March 3, 2025 (File No.
5 unchanged sentences
10.2e# Form of Performance Share Agreement pursuant to the 2020 OIP, amended in 2024 (incorporated by reference to Exhibit 10.2h to Alliant Energy’s Form 10-K for the year 2023 (File No.
−Removed: 10.2f# Form of Performance Share Agreement pursuant to the 2020 OIP, amended in 2025
−Removed: 10.2g# Form of Restricted Stock Unit Agreement pursuant to the 2020 OIP, amended in 2025
−Removed: Table of C o ntents
−Removed: Exhibit Number Description
−Removed: 10.3# DCP, as amended and restated effective November 1, 2024
−Removed: 10.4# IES Industries Inc.
−Removed: Amended and Restated Key Employee Deferred Compensation Agreement, as amended (incorporated by reference to Exhibit 10.7 to Alliant Energy’s Form 10-K for the year 2015 (File No.
+Added: 10.2f# Form of Performance Share Agreement pursuant to the 2020 OIP, amended in 2025 (incorporated by reference to Exhibit 10.2f to Alliant Energy's Form 10-K for the year 2024 (File No.
+Added: 10.2g# Form of Restricted Stock Unit Agreement pursuant to the 2020 OIP, amended in 2025 (incorporated by reference to Exhibit 10.2g to Alliant Energy's Form 10-K for the year 2024 (File No.
+Added: 10.3# DCP, as amended and restated effective November 1, 2024 (incorporated by reference to Exhibit 10.3 to Alliant Energy's Form 10-K for the year 2024 (File No.
10.4# Alliant Energy Rabbi Trust Agreement for DCPs (incorporated by reference to Exhibit 10.19 to Alliant Energy’s Form 10-K for the year 2005 (File No.
10.4a# Amendment to the Alliant Energy Rabbi Trust Agreement for DCPs (incorporated by reference to Exhibit 10.2 to Alliant Energy’s Form 10-Q for the quarter ended June 30, 2015 (File No.
+Added: Exhibit Number Description
10.4b# Second Amendment to the Alliant Energy Rabbi Trust Agreement for DCPs (incorporated by reference to Exhibit 10.3 to Alliant Energy’s Form 10-Q for the quarter ended June 30, 2015 (File No.
1 unchanged sentence
10.5a# Amendment to the Alliant Energy Excess Retirement Plan (incorporated by reference to Exhibit 10.4 to Alliant Energy’s Form 8-K, filed December 5, 2011 (File No.
−Removed: 10.7# Form of Supplemental Retirement Plan (SRP) Agreement by and between Alliant Energy and J.O.
−Removed: Larsen (incorporated by reference to Exhibit 10.3 to Alliant Energy’s Form 8-K, filed December 12, 2008 (File No.
10.6# Form of Key Executive Employment and Severance Agreement (KEESA), by and between Alliant Energy and L.M.
2 unchanged sentences
de Leon, M.N.
−Removed: Farlinger and R.
−Removed: Sundararajan (incorporated by reference to Exhibit 10.2 to Alliant Energy’s Form 8-K, filed October 28, 2021 (File No.
+Added: Farlinger, R.
+Added: Sundararajan, A.P.
+Added: Smyth and R.C.
+Added: Valcq (incorporated by reference to Exhibit 10.2 to Alliant Energy’s Form 8-K, filed October 28, 2021 (File No.
10.8# Executive Officer Severance Benefit Plan, as amended and restated, effective October 29, 2018 (incorporated by reference to Exhibit 10.1 to Alliant Energy’s Form 10-Q for the quarter ended September 30, 2018 (File No.
−Removed: 10.11# Terms of Alliant Energy Executive Short-term Incentive Plan
+Added: 10.9# Terms of Alliant Energy Executive Short-term Incentive Plan (incorporated by reference to Exhibit 10.11 to Alliant Energy's Form 10-K for the year 2024 (File No.
10.10# Form of Sign-On Bonus Reimbursement Agreement (incorporated by reference to Exhibit 10.14 to Alliant Energy ’ s Form 10-K for the year 2022 (File No .
1 unchanged sentence
10.12# Summary of Compensation and Benefits for Non-Employee Directors of Alliant Energy, IPL and WPL, effective January 1, 2026
−Removed: 19 Alliant Energy Insider Trading Policies and Procedures
+Added: 19 Alliant Energy Insider Trading Policies and Procedures (incorporated by reference to Exhibit 19 to Alliant Energy’s Form 10-K for the year 2024 (File No.
21.1 Subsidiaries of Alliant Energy
21 unchanged sentences
FORM 10-K SUMMARY
−Removed: Table of C o ntents
−Removed: Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrants have duly caused this report to be signed on their behalf by the undersigned, thereunto duly authorized on the 21st day of February 2025.
+Added: Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the Registrants have duly caused this report to be signed on their behalf by the undersigned, thereunto duly authorized on the 20th day of February 2026.
ALLIANT ENERGY INTERSTATE POWER WISCONSIN POWER
3 unchanged sentences
President and Chief Executive Officer Chief Executive Officer Chief Executive Officer
−Removed: Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the Registrants and in the capacities indicated on the 21st day of February 2025.
+Added: Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the Registrants and in the capacities indicated on the 20th day of February 2026.
ALLIANT ENERGY INTERSTATE POWER WISCONSIN POWER
9 unchanged sentences
Executive Vice President and Chief Financial Officer (Principal Financial Officer) Executive Vice President and Chief Financial Officer (Principal Financial Officer) Executive Vice President and Chief Financial Officer (Principal Financial Officer)
−Removed: /s/ Benjamin M.
−Removed: /s/ Benjamin M.
−Removed: /s/ Benjamin M.
−Removed: Bilitz Benjamin M.
−Removed: Bilitz Benjamin M.
+Added: Syse Dylan M.
+Added: Syse Dylan M.
Chief Accounting Officer and Controller (Principal Accounting Officer) Chief Accounting Officer and Controller (Principal Accounting Officer) Chief Accounting Officer and Controller (Principal Accounting Officer)
−Removed: Larsen, Chairman of the Board and Director John O.
−Removed: Larsen, Chairman of the Board and Director John O.
−Removed: Larsen, Chairman of the Board and Director
/s/ Patrick E.
1 unchanged sentence
/s/ Patrick E.
−Removed: Allen, Director
−Removed: Allen, Director
−Removed: Allen, Director
+Added: Allen, Board Chair and Director Patrick E.
+Added: Allen, Board Chair and Director Patrick E.
+Added: Allen, Board Chair and Director
/s/ Ignacio A.
38 unchanged sentences
Compared sentence by sentence after normalising whitespace, quotation marks, case and digits, so re-formatting and restated figures do not read as changed language. Wording changes appear as one removal and one addition. The current filing and the prior one are authoritative.