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AI Earnings Predictions for Alliant Energy Corporation (LNT)

Machine learning predictions based on historical earnings data and price patterns

Latest Prediction

SELL

1-Day Prediction

-1.38%

$70.03

0% positive prob.

5-Day Prediction

-1.97%

$69.61

0% positive prob.

20-Day Prediction

-0.84%

$70.41

0% positive prob.

Price at prediction: $71.01 Confidence: 100.0% Model AUC: 1.0000 Quarter: Q4 2025

Earnings Transcripts

SEC 8-K filings with transcript text

View All
2025
Q4

Q4 2025 Earnings

8-K SELL

Feb 20, 2026 · 100% conf.

AI Prediction SELL

1D

-1.38%

$70.03

Act: +1.27%

5D

-1.97%

$69.61

Act: +1.80%

20D

-0.84%

$70.41

Price: $71.01 Prob +5D: 0% AUC: 1.000
0000352541-26-000005

lnt-20260219000035254100000524850000107832false00003525412026-02-192026-02-190000352541lnt:IplMember2026-02-192026-02-190000352541lnt:WplMember2026-02-192026-02-19

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) February 19, 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 2.02 Results of Operations and Financial Condition.

On February 19, 2026, Alliant Energy Corporation issued a press release announcing its financial results for the fourth quarter and year ended December 31, 2025. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated February 19, 2026

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: February 19, 2026By: /s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: February 19, 2026By: /s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: February 19, 2026By: /s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

2025
Q3

Q3 2025 Earnings

8-K

Nov 7, 2025

0000352541-25-000079

lnt-20251106000035254100000524850000107832false00003525412025-11-062025-11-060000352541lnt:IplMember2025-11-062025-11-060000352541lnt:WplMember2025-11-062025-11-06

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) November 6, 2025

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 2.02 Results of Operations and Financial Condition.

On November 6, 2025, Alliant Energy Corporation issued a press release announcing its financial results for the three and nine months ended September 30, 2025. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated November 6, 2025

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: November 6, 2025By: /s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: November 6, 2025By: /s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: November 6, 2025By: /s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

2025
Q2

Q2 2025 Earnings

8-K

Aug 8, 2025

0000352541-25-000070

lnt-20250807000035254100000524850000107832false00003525412025-08-072025-08-070000352541lnt:IplMember2025-08-072025-08-070000352541lnt:WplMember2025-08-072025-08-07

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) August 7, 2025

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 2.02 Results of Operations and Financial Condition.

On August 7, 2025, Alliant Energy Corporation issued a press release announcing its financial results for the three and six months ended June 30, 2025. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated August 7, 2025

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: August 7, 2025By: /s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: August 7, 2025By: /s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: August 7, 2025By: /s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

2025
Q1

Q1 2025 Earnings

8-K

May 9, 2025

0000352541-25-000050

lnt-20250508000035254100000524850000107832false00003525412025-05-082025-05-080000352541lnt:IplMember2025-05-082025-05-080000352541lnt:WplMember2025-05-082025-05-08

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) May 8, 2025

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 2.02 Results of Operations and Financial Condition.

On May 8, 2025, Alliant Energy Corporation issued a press release announcing its financial results for the three months ended March 31, 2025. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated May 8, 2025

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: May 8, 2025By:/s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: May 8, 2025By:/s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: May 8, 2025By:/s/ Dylan M. Syse

Dylan M. Syse Chief Accounting Officer and Controller

2024
Q4

Q4 2024 Earnings

8-K

Feb 21, 2025

0000352541-25-000012

lnt-20250220000035254100000524850000107832false00003525412025-02-202025-02-200000352541lnt:IplMember2025-02-202025-02-200000352541lnt:WplMember2025-02-202025-02-20

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) February 20, 2025

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 2.02 Results of Operations and Financial Condition.

On February 20, 2025, Alliant Energy Corporation issued a press release announcing its financial results for the fourth quarter and year ended December 31, 2024. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated February 20, 2025

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: February 20, 2025By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: February 20, 2025By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: February 20, 2025By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2024
Q3

Q3 2024 Earnings

8-K

Nov 1, 2024

0000352541-24-000102

lnt-20241031000035254100000524850000107832false00003525412024-10-312024-10-310000352541lnt:IplMember2024-10-312024-10-310000352541lnt:WplMember2024-10-312024-10-31

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) October 31, 2024

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 2.02 Results of Operations and Financial Condition.

On October 31, 2024, Alliant Energy Corporation issued a press release announcing its financial results for the three and nine months ended September 30, 2024. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated October 31, 2024

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: October 31, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: October 31, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: October 31, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2024
Q2

Q2 2024 Earnings

8-K

Aug 2, 2024

0000352541-24-000087

lnt-20240801000035254100000524850000107832false00003525412024-08-012024-08-010000352541lnt:IplMember2024-08-012024-08-010000352541lnt:WplMember2024-08-012024-08-01

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) August 1, 2024

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 2.02 Results of Operations and Financial Condition.

On August 1, 2024, Alliant Energy Corporation issued a press release announcing its financial results for the three and six months ended June 30, 2024. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated August 1, 2024

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: August 1, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: August 1, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: August 1, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2024
Q1

Q1 2024 Earnings

8-K

May 3, 2024

0000352541-24-000054

lnt-20240502000035254100000524850000107832false00003525412024-05-022024-05-020000352541lnt:IplMember2024-05-022024-05-020000352541lnt:WplMember2024-05-022024-05-02

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) May 2, 2024

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 2.02 Results of Operations and Financial Condition.

On May 2, 2024, Alliant Energy Corporation issued a press release announcing its financial results for the three months ended March 31, 2024. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated May 2, 2024

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: May 2, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: May 2, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: May 2, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2023
Q4

Q4 2023 Earnings

8-K

Feb 16, 2024

0000352541-24-000011

lnt-20240215000035254100000524850000107832false00003525412024-02-152024-02-150000352541lnt:IplMember2024-02-152024-02-150000352541lnt:WplMember2024-02-152024-02-15

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) February 15, 2024

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 2.02 Results of Operations and Financial Condition.

On February 15, 2024, Alliant Energy Corporation issued a press release announcing its financial results for the fourth quarter and year ended December 31, 2023. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated February 15, 2024

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: February 15, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: February 15, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: February 15, 2024By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2023
Q3

Q3 2023 Earnings

8-K

Nov 3, 2023

0000352541-23-000106

lnt-20231102000035254100000524850000107832false00003525412023-11-022023-11-020000352541lnt:IplMember2023-11-022023-11-020000352541lnt:WplMember2023-11-022023-11-02

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) November 2, 2023

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 2.02 Results of Operations and Financial Condition.

On November 2, 2023, Alliant Energy Corporation issued a press release announcing its financial results for the three and nine months ended September 30, 2023. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated November 2, 2023

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: November 2, 2023By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: November 2, 2023By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: November 2, 2023By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2023
Q2

Q2 2023 Earnings

8-K

Aug 4, 2023

0000352541-23-000088

lnt-20230803000035254100000524850000107832false00003525412023-08-032023-08-030000352541lnt:IplMember2023-08-032023-08-030000352541lnt:WplMember2023-08-032023-08-03

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) August 3, 2023

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 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 2.02 Results of Operations and Financial Condition.

On August 3, 2023, Alliant Energy Corporation issued a press release announcing its financial results for the three and six months ended June 30, 2023. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated August 3, 2023

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: August 3, 2023By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: August 3, 2023By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: August 3, 2023By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2023
Q1

Q1 2023 Earnings

8-K

May 5, 2023

0000352541-23-000056

lnt-20230504000035254100000524850000107832false00003525412023-05-042023-05-040000352541lnt:IplMember2023-05-042023-05-040000352541lnt:WplMember2023-05-042023-05-04

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) May 4, 2023

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 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 2.02 Results of Operations and Financial Condition.

On May 4, 2023, Alliant Energy Corporation issued a press release announcing its financial results for the three months ended March 31, 2023. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated May 4, 2023

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: May 4, 2023By:/s/ Benjamin M. Bilitz Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: May 4, 2023By:/s/ Benjamin M. Bilitz Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: May 4, 2023By:/s/ Benjamin M. Bilitz Benjamin M. Bilitz Chief Accounting Officer and Controller

2022
Q4

Q4 2022 Earnings

8-K

Feb 24, 2023

0000352541-23-000012

lnt-20230223000035254100000524850000107832false00003525412023-02-232023-02-230000352541lnt:IplMember2023-02-232023-02-230000352541lnt:WplMember2023-02-232023-02-23

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) February 23, 2023

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 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 2.02 Results of Operations and Financial Condition.

On February 23, 2023, Alliant Energy Corporation issued a press release announcing its financial results for the fourth quarter and year ended December 31, 2022. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated February 23, 2023

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: February 23, 2023By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: February 23, 2023By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: February 23, 2023By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2022
Q3

Q3 2022 Earnings

8-K

Nov 8, 2022

0000352541-22-000080

lnt-20221107000035254100000524850000107832false00003525412022-11-072022-11-070000352541lnt:IplMember2022-11-072022-11-070000352541lnt:WplMember2022-11-072022-11-07

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) November 7, 2022

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 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 2.02 Results of Operations and Financial Condition.

On November 7, 2022, Alliant Energy Corporation issued a press release announcing its financial results for the three and nine months ended September 30, 2022. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated November 7, 2022

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: November 7, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: November 7, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: November 7, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2022
Q2

Q2 2022 Earnings

8-K

Aug 5, 2022

0000352541-22-000073

lnt-20220804000035254100000524850000107832false00003525412022-08-042022-08-040000352541lnt:IplMember2022-08-042022-08-040000352541lnt:WplMember2022-08-042022-08-04

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) August 4, 2022

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 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 2.02 Results of Operations and Financial Condition.

On August 4, 2022, Alliant Energy Corporation issued a press release announcing its financial results for the three and six months ended June 30, 2022. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated August 4, 2022

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: August 4, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: August 4, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: August 4, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2022
Q1

Q1 2022 Earnings

8-K

Apr 29, 2022

0000352541-22-000056

lnt-20220428000035254100000524850000107832false00003525412022-04-282022-04-280000352541lnt:IplMember2022-04-282022-04-280000352541lnt:WplMember2022-04-282022-04-28

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) April 28, 2022

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 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 2.02 Results of Operations and Financial Condition.

On April 28, 2022, Alliant Energy Corporation issued a press release announcing its financial results for the three months ended March 31, 2022. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated April 28, 2022

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: April 28, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: April 28, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: April 28, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2021
Q4

Q4 2021 Earnings

8-K

Feb 18, 2022

0000352541-22-000018

lnt-20220217000035254100000524850000107832false00003525412022-02-172022-02-170000352541lnt:IplMember2022-02-172022-02-170000352541lnt:WplMember2022-02-172022-02-17

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) February 17, 2022

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 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 2.02 Results of Operations and Financial Condition.

On February 17, 2022, Alliant Energy Corporation issued a press release announcing its financial results for the fourth quarter and year ended December 31, 2021. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated February 17, 2022

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: February 17, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: February 17, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: February 17, 2022By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2021
Q3

Q3 2021 Earnings

8-K

Nov 5, 2021

0000352541-21-000093

lnt-20211104000035254100000524850000107832false00003525412021-11-042021-11-040000352541lnt:IplMember2021-11-042021-11-040000352541lnt:WplMember2021-11-042021-11-04

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) November 4, 2021

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 Interstate Power and Light Company, 5.100% Series D Cumulative Perpetual Preferred Stock, $0.01 Par Value, Trading Symbol IPLDP, 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 2.02 Results of Operations and Financial Condition.

On November 4, 2021, Alliant Energy Corporation issued a press release announcing its financial results for the three and nine months ended September 30, 2021. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated November 4, 2021

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: November 4, 2021By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: November 4, 2021By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: November 4, 2021By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2021
Q2

Q2 2021 Earnings

8-K

Aug 6, 2021

0000352541-21-000073

lnt-20210805000035254100000524850000107832false00003525412021-08-052021-08-050000352541lnt:IplMember2021-08-052021-08-050000352541lnt:WplMember2021-08-052021-08-05

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) August 5, 2021

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 Interstate Power and Light Company, 5.100% Series D Cumulative Perpetual Preferred Stock, $0.01 Par Value, Trading Symbol IPLDP, 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 2.02 Results of Operations and Financial Condition.

On August 5, 2021, Alliant Energy Corporation issued a press release announcing its financial results for the three and six months ended June 30, 2021. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated August 5, 2021

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: August 5, 2021By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: August 5, 2021By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: August 5, 2021By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

2021
Q1

Q1 2021 Earnings

8-K

May 7, 2021

0000352541-21-000054

lnt-20210506000035254100000524850000107832false00003525412021-05-062021-05-060000352541lnt:IplMember2021-05-062021-05-060000352541lnt:WplMember2021-05-062021-05-06

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) May 6, 2021

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 Interstate Power and Light Company, 5.100% Series D Cumulative Perpetual Preferred Stock, $0.01 Par Value, Trading Symbol IPLDP, 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 2.02 Results of Operations and Financial Condition.

On May 6, 2021, Alliant Energy Corporation issued a press release announcing its financial results for the three months ended March 31, 2021. A copy of such press release is furnished as Exhibit 99.1 and is incorporated by reference herein.

Item 9.01 Financial Statements and Exhibits.

(a)Not applicable. (b)Not applicable. (c)Not applicable. (d)Exhibits. The following exhibits are being furnished herewith:

Exhibit NumberDescription (99.1)Alliant Energy Corporation press release dated May 6, 2021

(104)Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned hereunto duly authorized.

ALLIANT ENERGY CORPORATION

Date: May 6, 2021By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

INTERSTATE POWER AND LIGHT COMPANY

Date: May 6, 2021By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

WISCONSIN POWER AND LIGHT COMPANY

Date: May 6, 2021By:/s/ Benjamin M. Bilitz

Benjamin M. Bilitz Chief Accounting Officer and Controller

About Alliant Energy Corporation (LNT) Earnings

This page provides Alliant Energy Corporation (LNT) earnings call transcripts from SEC 8-K filings along with AI-powered predictions for post-earnings price movements. Our machine learning models analyze historical earnings data, pre-earnings price patterns, volume changes, and volatility to predict 1-day, 5-day, and 20-day returns after each earnings release.

Earnings transcripts are sourced directly from SEC EDGAR filings. Predictions are generated using gradient boosting models trained on LNT's historical earnings reactions. All predicted returns are shown as percentages, and predicted prices are calculated from the closing price at the time of prediction. Past performance does not guarantee future results.

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