Manu Asthana joins Alliant Energy (NASDAQ: LNT) board and audit panel

Rhea-AI Filing Summary

Alliant Energy Corporation and its utility subsidiaries are expanding their boards and adding a new independent director. On January 5, 2026, the boards of Alliant Energy, Interstate Power and Light Company, and Wisconsin Power and Light Company increased their board size to 11 members and appointed Manu Asthana as a director effective February 23, 2026.

Asthana, 52, previously served as President and Chief Executive Officer of PJM Interconnection from 2020 to 2025, an organization that oversees the largest power grid in North America, serving 67 million people across 13 states and the District of Columbia. He will stand for election at Alliant Energy’s 2026 Annual Meeting of Shareowners as a nominee to serve until the 2029 Annual Meeting, alongside three directors whose terms expire in 2026.

Effective February 23, 2026, he will join the Audit Committee and Operations Committee of each board. For 2026 board service, he will receive non-employee director compensation in line with existing practices, with an annual retainer of $300,000 for service on all three boards.

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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 OR 15(d) of The Securities Exchange Act of 1934

Date of Report (Date of earliest event reported) January 5, 2026

Name of Registrant, State of Incorporation, Address of Principal Executive Offices, Telephone Number, Commission File Number, IRS Employer Identification Number

ALLIANT ENERGY CORPORATION

(a Wisconsin Corporation)

4902 N. Biltmore Lane

Madison, Wisconsin 53718

Telephone (608) 458-3311

Commission File Number - 1-9894

IRS Employer Identification Number - 39-1380265

INTERSTATE POWER & LIGHT COMPANY

(an Iowa corporation)

Alliant Energy Tower

Cedar Rapids, Iowa 52401

Telephone (319) 786-4411

Commission File Number - 1-4117

IRS Employer Identification Number - 42-0331370

WISCONSIN POWER & LIGHT COMPANY

(a Wisconsin corporation)

4902 N. Biltmore Lane

Madison, Wisconsin 53718

Telephone (608) 458-3311

Commission File Number - 0-337

IRS Employer Identification Number - 39-0714890

(Former name or former address, if changed since last report.)

This combined Form 8-K is separately filed by Alliant Energy Corporation, Interstate Power and Light Company and Wisconsin Power and Light Company.

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

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

Alliant Energy Corporation, Common Stock, $0.01 Par Value, Trading Symbol LNT, Nasdaq Global Select Market

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Alliant Energy Corporation - Emerging growth company ☐

Interstate Power and Light Company - Emerging growth company ☐

Wisconsin Power and Light Company - Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has 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.

Alliant Energy Corporation ☐

Interstate Power and Light Company ☐

Wisconsin Power and Light Company ☐

Item 5.02    Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

On January 5, 2026, the Boards of Directors (the “Boards”) of Alliant Energy Corporation (“Alliant Energy”), Interstate Power and Light Company and Wisconsin Power and Light Company increased the number of directors on the Boards to 11 and appointed Manu Asthana as a member of the Boards effective February 23, 2026. Mr. Asthana, 52, was President and Chief Executive Officer of PJM Interconnection from 2020 to 2025. PJM Interconnection oversees the largest power grid in North America and one of the largest electricity markets in the world, serving 67 million people in 13 states and the District of Columbia. Prior to that, he held roles of increasing importance with accountabilities related to financial performance, risk, and operations at public and private utility companies. Mr. Asthana will stand for election at the Alliant Energy 2026 Annual Meeting of Shareowners as a nominee for director to serve until Alliant Energy’s 2029 Annual Meeting of Shareowners, along with the three directors whose terms expire at the 2026 Annual Meeting of Shareowners.

Effective February 23, 2026, Mr. Asthana will serve as a member of the Audit Committee and the Operations Committee of each Board. He will receive compensation as a non-employee director in accordance with the non-employee director compensation practices described in Alliant Energy’s Definitive Proxy Statement filed with the Securities and Exchange Commission on April 1, 2025, except that for 2026 Board service, the annual retainer for service on all Boards will be $300,000.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, Alliant Energy Corporation, Interstate Power and Light Company and Wisconsin Power and Light Company have each duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

			ALLIANT ENERGY CORPORATION
Date: January 8, 2026			By:/s/ Omar N. Chaudhary
			Omar N. Chaudhary
			Corporate Secretary

			INTERSTATE POWER AND LIGHT COMPANY
Date: January 8, 2026			By:/s/ Omar N. Chaudhary
			Omar N. Chaudhary
			Corporate Secretary

			WISCONSIN POWER AND LIGHT COMPANY
Date: January 8, 2026			By:/s/ Omar N. Chaudhary
			Omar N. Chaudhary
			Corporate Secretary

FAQ

What board change did Alliant Energy (LNT) disclose in this 8-K?

Alliant Energy and its utility subsidiaries increased the size of their boards to 11 directors and appointed Manu Asthana as a new board member effective February 23, 2026.

Who is Manu Asthana, the new director at Alliant Energy (LNT)?

Manu Asthana, age 52, was President and Chief Executive Officer of PJM Interconnection from 2020 to 2025. PJM oversees the largest power grid in North America and one of the largest electricity markets in the world, serving 67 million people in 13 states and the District of Columbia.

When will Manu Asthana stand for election to Alliant Energy’s board?

Manu Asthana will stand for election at Alliant Energy’s 2026 Annual Meeting of Shareowners as a nominee for director to serve until the company’s 2029 Annual Meeting of Shareowners, along with the three directors whose terms expire at the 2026 meeting.

Which board committees will Manu Asthana join at Alliant Energy (LNT)?

Effective February 23, 2026, Manu Asthana will serve on the Audit Committee and the Operations Committee of each of the three boards: Alliant Energy Corporation, Interstate Power and Light Company, and Wisconsin Power and Light Company.

How will the new Alliant Energy director be compensated in 2026?

For 2026 board service, Manu Asthana will receive non-employee director compensation consistent with Alliant Energy’s disclosed practices, with an annual retainer of $300,000 for service on all three boards.

Which companies are covered by this combined Alliant Energy 8-K filing?

This combined report is filed separately by Alliant Energy Corporation, Interstate Power and Light Company, and Wisconsin Power and Light Company, each reflecting the same director appointment and board size change.