What changed in this filing

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Item 9A. Controls and Procedures

2025-02-21 compared with 2024-02-16 · 54 added, 53 removed, 320 unchanged (25% of the section changed)

44 unchanged sentences

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.

The information required by Item 10 relating to directors and nominees for election of directors at the 2024 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, and Alliant Energy’s, IPL’s and WPL’s Code of Conduct is incorporated herein by reference to the relevant information in the 2024 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.

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.

The code of ethics, also referred to as the Code of Conduct, of Alliant Energy, IPL and WPL are the same.

5 unchanged sentences

Information regarding Alliant Energy’s equity compensation plans as of December 31, 2024 was as follows:

Number of securities to be (B) Number of securities remaining available

issued upon exercise of Weighted-average exercise for future issuance under equity

outstanding options, price of outstanding options, compensation plans (excluding

Number of securities to be Weighted-average Number of securities remaining available

issued upon exercise of exercise price of for future issuance under equity

outstanding options, outstanding options, compensation plans (excluding

Plan Category warrants and rights warrants and rights securities reflected in column (A))

2 unchanged sentences

1,529,346 $51.63 7,107,084

(a) Represents performance shares, performance restricted stock units and restricted stock units granted under the 2020 OIP, all of which are paid out in shares of Alliant Energy’s common stock.

The performance share and performance restricted stock unit awards included in column (A) of the table reflect an assumed payout at the maximum performance multiplier of 200%.

Also included are restricted stock units granted under the 2020 OIP, which vest at the expiration of a three-year time-vesting period.

(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.

The performance share awards reflect an assumed payout at the maximum performance multiplier of 200%.

The restricted stock units vest at the expiration of a three-year time-vesting period.

(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.

As of December 31, 2023, there were performance shares and restricted stock units (performance- and time-vesting) outstanding under the 2020 OIP, the only plan under which such equity awards are currently granted.

As of December 31, 2024, there were performance shares and restricted stock units outstanding under the 2020 OIP, the only plan under which such equity awards are currently granted.

(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) .

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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.

IPL’s and WPL’s tax fees for 2023 and 2022 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.

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.

All other fees for 2024 and 2023 for IPL and WPL consisted of license fees for accounting research software products and seminars.

The Audit Committee does not consider the provision of non-audit services by the independent registered public accounting firm described above to be incompatible with maintaining independence of the independent registered public accounting firm.

Table of C o ntents

EXHIBITS, FINANCIAL STATEMENT SCHEDULES

(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.

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(2) Financial Statement Schedules -

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Notes receivable from affiliated companies $ 103 $ 96

Income tax refunds receivable 12 —

Total current assets 117 97

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Current liabilities:

Current maturities of long-term debt $ 571 $ —

Commercial paper 325 157

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Total current liabilities 2,307 1,235

Long-term debt, net 568 —

Long-term debt, net (excluding current portion) — 568

Other liabilities 3 2

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Net change in notes receivable from and payable to affiliates 326 ( 281 ) 369

Dividends from consolidated subsidiaries in excess of equity earnings — — 50

Net cash flows used for investing activities ( 54 ) ( 606 ) ( 161 )

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Supplemental cash flows information:

Cash (paid) refunded during the period for:

Cash (paid) received during the period for:

Interest ($ 40 ) ($ 27 ) ($ 6 )

6 unchanged sentences

In the Condensed Financial Statements of Alliant Energy Corporation (Parent Company Only), investments in subsidiaries are accounted for using the equity method.

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SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS AND RESERVES

15 unchanged sentences

The above provisions relate to various customer, notes and other receivable balances included in various line items on the respective balance sheets.

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(a) Deductions are of the nature for which the reserves were created.

14 unchanged sentences

4.1 Amended and Restated Five-Year Master Credit Agreement, effective December 17, 2021 , among Alliant Energy, IPL, WPL, Wells Fargo Bank, National Association (N.A.) and the lender parties set forth therein (incorporated by reference to Exhibit 4.1 to Alliant Energy’s Form 8-K, filed December 21, 20 21 (File No.

4.1a First Amendment to Amended and Restated Five-Year Master Credit Agreement, effective March 15, 2023, among Alliant Energy, IPL, WPL, Wells Fargo Bank, N.A .

and the lender parties set forth therein (incorporated by reference to Exhibit 4.1 to Alliant Energy’s Form 10 - Q for the quarter ended March 31, 202 3 (File No.

4.1a First Amendment to Amended and Restated Five-Year Master Credit Agreement, effective March 15, 2023, among Alliant Energy, IPL, WPL, Wells Fargo Bank, N ational A ssociat ion and the lender parties set forth therein (incorporated by reference to Exhibit 4.1 to Alliant Energy’s Form 10 - Q for the quarter ended March 31, 202 3 (File No.

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.

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.

1 unchanged sentence

4.4 Indenture, dated as of November 20, 2020, 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 November 23, 2020 (File No.

Table of C o ntents

Exhibit Number Description

4.5 Indenture, dated as of February 28, 2022, 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 March 1, 2022 (File No.

4.6 Indenture, dated as of November 10, 2023, 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 November 13, 2023 (File No.

4.7 Indenture, dated as of June 6, 2024, 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 6, 2024 (File No.

4.8 Indenture, dated as of June 20, 1997, between WPL and U.S.

2 unchanged sentences

2 to WPL’s Registration Statement on Form S-3 (Reg.

4.7a First Supplemental Indenture, dated September 16, 2021, among WPL, Wells Fargo Bank, N.A., as Original Trustee, and U.S.

, as Series Trustee (incorporated by reference to Exhibit 4.1 to WPL's Form 8-K, filed September 16, 2021 (File No.

4.8a First Supplemental Indenture, dated September 16, 2021, among WPL, Wells Fargo Bank, N ational A ssociation , as Original Trustee, and U.S.

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.

4.9 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

4.12 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.

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Exhibit Number Description

4.13 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.

3 unchanged sentences

4.17 Officers’ Certificate, dated as of March 30, 2023, creating WPL's 4.950% Debentures due April 1, 2033 (incorporated by reference to Exhibit 4.1 to WPL's Form 8-K, filed March 30, 2023 (File No.

4.18 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.

4.19 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.

6 unchanged sentences

4.24 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.

4.23 Officer’s Certificate, dated as of November 24, 2014, creating IPL’s 3.25% Senior Debentures due December 1, 2024 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed November 24, 2014 (File No.

4.23a Officer’s Certificate, dated as of November 15, 2017, reopening IPL’s 3.25% Senior Debentures due December 1, 2024 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed November 15, 2017 (File No.

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.

6 unchanged sentences

4.32 Officer’s Certificate, dated as of September 21, 2023, creating IPL’s 5.70% Senior Debentures due October 15, 2033 (incorporated by reference to Exhibit 4.1 to IPL’s Form 8-K, filed September 21, 2023 (File No.

4.32 Description of Common Stock of Alliant Energy

10.1 Term Loan Credit Agreement, dated as of March 3, 2022, among AEF, Alliant Energy, U.S.

and the lender parties set forth therein (incorporated by reference to Exhibit 10.1 to Alliant Energy’s Form 8-K, filed March 4, 2022 (File No.

4.33 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.

4.34 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.

10.1 Amended and Restated Term Loan Credit Agreement, dated as of March 1, 2024, 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 5, 2024 (File No.

10.2# 2020 O I P (incorporated by reference to Appendix A to Alliant Energy’s definitive proxy statement filed on Schedule 14A on April 9, 2020 (File No.

10.2a# Form of Performance Share Agreement pursuant to the 2020 OIP, amended in 2022 (incorporated by reference to Exhibit 10.3d to Alliant Energy’s Form 10-K for the year 2021 (File No.

10.2b# Form of Restricted Stock Unit Agreement pursuant to the 2020 OIP, amended in 2022 (incorporated by reference to Exhibit 10.3e to Alliant Energy’s Form 10-K for the year 2021 (File No.

10.2c# Form of Performance Restricted Stock Unit Agreement (Workforce Composition Metric) pursuant to the 2020 OIP, amended in 2022 (incorporated by reference to Exhibit 10.3f to Alliant Energy’s Form 10-K for the year 2021 (File No.

10.2d# Form of Performance Restricted Stock Unit Agreement (Net Income Metric) pursuant to the 2020 OIP, amended in 2022 (incorporated by reference to Exhibit 10.3g to Alliant Energy’s Form 10-K for the year 2021 (File No.

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.

10.2f# Form of Performance Share Agreement pursuant to the 2020 OIP, amended in 2025

10.2g# Form of Restricted Stock Unit Agreement pursuant to the 2020 OIP, amended in 2025

Table of C o ntents

Exhibit Number Description

10.1a Incremental Term Loan Amendment, dated as of December 7, 2022, among AEF, Alliant Energy, CoBank ACB as incremental lender, and U.S.

as administrative agent (incorporated by reference to Exhibit 10.1a to Alliant Energy's Form 10-K for the year 2022 (File No .

10.2# 2020 O I P (incorporated by reference to Appendix A to Alliant Energy’s definitive proxy statement filed on Schedule 14A on April 9, 2020 (File No.

10.2a# Form of Performance Share Agreement pursuant to the 2020 O I P (incorporated by reference to Exhibit 10.1a to Alliant Energy’s Form 10-Q for the quarter ended June 30, 2020 (File No.

10.2b# Form of Restricted Stock Unit Agreement pursuant to the 2020 O IP (incorporated by reference to Exhibit 10.1b to Alliant Energy’s Form 10-Q for the quarter ended June 30, 2020 (File No.

10.2c# Form of Performance Restricted Stock Unit Agreement pursuant to the 2020 OIP (incorporated by reference to Exhibit 10.1c to Alliant Energy’s Form 10-Q for the quarter ended June 30, 2020 (File No.

10.2d# Form of Performance Share Agreement pursuant to the 2020 OIP, amended in 2022 (incorporated by reference to Exhibit 10.3d to Alliant Energy’s Form 10-K for the year 2021 (File No.

10.2e# Form of Restricted Stock Unit Agreement pursuant to the 2020 OIP, amended in 2022 (incorporated by reference to Exhibit 10.3e to Alliant Energy’s Form 10-K for the year 2021 (File No.

10.2f# Form of Performance Restricted Stock Unit Agreement (Diversity Metric) pursuant to the 2020 OIP, amended in 2022 (incorporated by reference to Exhibit 10.3f to Alliant Energy’s Form 10-K for the year 2021 (File No.

10.2g# Form of Performance Restricted Stock Unit Agreement (Net Income Metric) pursuant to the 2020 OIP, amended in 2022 (incorporated by reference to Exhibit 10.3g to Alliant Energy’s Form 10-K for the year 2021 (File No.

10.2h# Form of Performance Share Agreement pu rsuant to t he 2020 OIP, amended in 2024

10.3# DCP, as amended and restated effective January 1, 2011 (incorporated by reference to Exhibit 10.1 to Alliant Energy’s Form 8-K, filed December 14, 2010 (File No.

10.3a# Amendment to the DCP, as amended and restated (incorporated by reference to Exhibit 10.2 to Alliant Energy’s Form 8-K, filed December 5, 2011 (File No.

10.3b# Amendment to the DCP, as amended and restated (incorporated by reference to Exhibit 10.4b to Alliant Energy's Form 10-K for the year 2022 (File No .

10.3# DCP, as amended and restated effective November 1, 2024

10.4# IES Industries Inc.

7 unchanged sentences

Larsen (incorporated by reference to Exhibit 10.3 to Alliant Energy’s Form 8-K, filed December 12, 2008 (File No.

10.8# Form of Key Executive Employment and Severance Agreement (KEESA), by and between Alliant Energy and eac h of J.O.

Larsen and L.M.

10.8# Form of Key Executive Employment and Severance Agreement (KEESA), by and between Alliant Energy and L.M.

Barton (incorporated by reference to Exhibit 10.1 to Alliant Energy’s Form 8-K, filed October 28, 2021 (File No.

10.9# Form of KEESA, by and between Alliant Energy and each of R.J.

de Leon , T.L.

Kouba and R .

de Leon, M.N.

Farlinger and R.

Sundararajan (incorporated by reference to Exhibit 10.2 to Alliant Energy’s Form 8-K, filed October 28, 2021 (File No.

10.10# 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.

10.11# Terms of Alliant Energy Executive Sho rt-term Incentive Plan

10.11# Terms of Alliant Energy Executive Short-term Incentive Plan

10.12# 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 .

10.13# Form of Relocation Reimbursement Agreement

10.13# Form of Relocation Reimbursement Agreement (incorporated by reference to Exhibit 10.13 to Alliant Energy ’ s Form 10-K for the year 2023 (File No.

10.14# Summary of Compensation and Benefits for Non-Employee Directors of Alliant Energy, IPL and WPL, effective January 1, 2025

19 Alliant Energy Insider Trading Policies and Procedures

21.1 Subsidiaries of Alliant Energy

10 unchanged sentences

32.2 Written Statement of the Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C.§1350 for IPL

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Exhibit Number Description

32.3 Written Statement of the Chief Executive Officer and Chief Financial Officer Pursuant to 18 U.S.C.§1350 for WPL

97 Alliant Energy Incentive Compensation Re covery Policy

97 Alliant Energy Incentive Compensation Recovery Policy (incorporated by reference to Exhibit 97 to Alliant Energy’s Form 10-K for the year ended 2023 (File No.

101.INS Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document

8 unchanged sentences

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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 16th day of February 2024.

ALLIANT ENERGY INTERSTATE POWER WISCONSIN POWER

3 unchanged sentences

President and Chief Executive Officer Chief Executive Officer Chief Executive Officer

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 16th day of February 2024.

ALLIANT ENERGY INTERSTATE POWER WISCONSIN POWER

15 unchanged sentences

Chief Accounting Officer and Controller (Principal Accounting Officer) Chief Accounting Officer and Controller (Principal Accounting Officer) Chief Accounting Officer and Controller (Principal Accounting Officer)

Larsen, Executive Chairman, Chairman of the Board and Director John O.

Larsen, Executive Chairman, Chairman of the Board and Director

Larsen, Chairman of the Board and Director John O.

Larsen, Chairman of the Board and Director

/s/ Patrick E.

34 unchanged sentences

O’Toole, Director

/s/ Christie Raymond

Christie Raymond, Director

Sanders, Director

2 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.

What changed 10-K

Item 9A. Controls and Procedures