Alliant Energy Corp SEC filings LNT
Alliant Energy Corp has 1,000 filings in SEC EDGAR's recent list, going back to Jan 31, 2014. Its latest annual report, Form ARS, was filed on Mar 31, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Oct 30, 2026, covering the quarter ended Sep 30, 2026. The most recent current report (Form 8-K) was filed on Oct 30, 2026 (results of operations). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| 10-Q | Quarterly report | Oct 30, 2026 | Sep 30, 2026 |
| 8-K |
Current report
Results of operations
|
Oct 30, 2026 | Oct 29, 2026 |
| 8-K |
Current report
Material agreement, New debt
|
Oct 28, 2026 | Oct 26, 2026 |
| 4 | Insider transaction | Oct 14, 2026 | Oct 9, 2026 |
| 4 | Insider transaction | Oct 14, 2026 | Oct 9, 2026 |
| 4 | Insider transaction | Oct 14, 2026 | Oct 9, 2026 |
| 4 | Insider transaction | Oct 14, 2026 | Oct 9, 2026 |
| 4 | Insider transaction | Oct 14, 2026 | Oct 9, 2026 |
| 4 | Insider transaction | Oct 14, 2026 | Oct 9, 2026 |
| 4 | Insider transaction | Oct 14, 2026 | Oct 9, 2026 |
| 4 | Insider transaction | Oct 14, 2026 | Oct 9, 2026 |
| 8-K |
Current report
Other events
|
Aug 21, 2026 | Aug 21, 2026 |
| 4 | Insider transaction | Aug 12, 2026 | Aug 10, 2026 |
| 10-Q | Quarterly report | Jul 31, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Results of operations
|
Jul 31, 2026 | Jul 30, 2026 |
| 4 | Insider transaction | Jul 14, 2026 | Jul 10, 2026 |
| 4 | Insider transaction | Jul 14, 2026 | Jul 10, 2026 |
| 4 | Insider transaction | Jul 14, 2026 | Jul 10, 2026 |
| 4 | Insider transaction | Jul 14, 2026 | Jul 10, 2026 |
| 4 | Insider transaction | Jul 14, 2026 | Jul 10, 2026 |
| 4 | Insider transaction | Jul 14, 2026 | Jul 10, 2026 |
| 4 | Insider transaction | Jul 14, 2026 | Jul 10, 2026 |
| 4 | Insider transaction | Jul 14, 2026 | Jul 10, 2026 |
| 11-K | Employee savings plan report | Jun 16, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Shareholder vote results
|
May 21, 2026 | May 20, 2026 |
| 10-Q | Quarterly report | May 1, 2026 | Mar 31, 2026 |
| 8-K |
Current report
Results of operations
|
May 1, 2026 | Apr 30, 2026 |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 29, 2026 | — |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 28, 2026 | — |
| 4 | Insider transaction | Apr 16, 2026 | Apr 15, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 10, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 10, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 10, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 10, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 10, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 10, 2026 |
| 4 | Insider transaction | Apr 14, 2026 | Apr 10, 2026 |
| ARS | Annual report to shareholders | Mar 31, 2026 | Dec 31, 2025 |
| DEFA14A | Additional proxy material | Mar 31, 2026 | — |
| DEF 14A | Proxy statement | Mar 31, 2026 | May 20, 2026 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Mar 26, 2026 | — |
| 8-K |
Current report
Material agreement
|
Mar 19, 2026 | Mar 19, 2026 |
| 424B5 | Prospectus supplement | Mar 19, 2026 | — |
| 4/A | Form 4/a | Mar 19, 2026 | Feb 19, 2026 |
| 3 | Initial insider ownership | Mar 4, 2026 | Feb 23, 2026 |
| 8-K |
Current report
Material agreement, New debt
|
Mar 4, 2026 | Mar 2, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 19, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 19, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 19, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 19, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 19, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 19, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 19, 2026 |
| 4 | Insider transaction | Feb 23, 2026 | Feb 19, 2026 |
| 10-K | Annual report | Feb 20, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Results of operations
|
Feb 20, 2026 | Feb 19, 2026 |
| S-8 POS | Filing | Feb 9, 2026 | — |
| S-8 POS | Filing | Feb 9, 2026 | — |
| S-8 POS | Filing | Feb 9, 2026 | — |
| S-8 POS | Filing | Feb 9, 2026 | — |
| S-8 POS | Filing | Feb 9, 2026 | — |
| S-8 POS | Filing | Feb 9, 2026 | — |
| S-8 POS | Filing | Feb 9, 2026 | — |
| 3 | Initial insider ownership | Jan 15, 2026 | Jan 5, 2026 |
| 4 | Insider transaction | Jan 12, 2026 | Jan 9, 2026 |
| 4 | Insider transaction | Jan 12, 2026 | Jan 9, 2026 |
| 4 | Insider transaction | Jan 12, 2026 | Jan 9, 2026 |
| 4 | Insider transaction | Jan 12, 2026 | Jan 9, 2026 |
| 4 | Insider transaction | Jan 12, 2026 | Jan 9, 2026 |
| 4 | Insider transaction | Jan 12, 2026 | Jan 9, 2026 |
| 4 | Insider transaction | Jan 12, 2026 | Jan 9, 2026 |
| 8-K |
Current report
Officer or director change
|
Jan 8, 2026 | Jan 5, 2026 |
| 8-K |
Current report
Officer or director change
|
Dec 16, 2025 | Dec 10, 2025 |
| 8-K |
Current report
Other events
|
Dec 5, 2025 | Dec 2, 2025 |
| 10-Q | Quarterly report | Nov 7, 2025 | Sep 30, 2025 |
| 8-K |
Current report
Results of operations
|
Nov 7, 2025 | Nov 6, 2025 |
| 4 | Insider transaction | Oct 14, 2025 | Oct 10, 2025 |
| 4 | Insider transaction | Oct 14, 2025 | Oct 10, 2025 |
| 4 | Insider transaction | Oct 14, 2025 | Oct 10, 2025 |
| 4 | Insider transaction | Oct 14, 2025 | Oct 10, 2025 |
| 4 | Insider transaction | Oct 14, 2025 | Oct 10, 2025 |
| 4 | Insider transaction | Oct 14, 2025 | Oct 10, 2025 |
| 8-K |
Current report
Other events
|
Sep 26, 2025 | Sep 23, 2025 |
| 424B5 | Prospectus supplement | Sep 25, 2025 | — |
| FWP | Free writing prospectus | Sep 23, 2025 | — |
| 424B5 | Prospectus supplement | Sep 23, 2025 | — |
| POSASR | Filing | Sep 22, 2025 | — |
| 8-K |
Current report
Other events
|
Sep 11, 2025 | Sep 8, 2025 |
| 10-Q | Quarterly report | Aug 8, 2025 | Jun 30, 2025 |
| 8-K |
Current report
Results of operations
|
Aug 8, 2025 | Aug 7, 2025 |
| 4 | Insider transaction | Jul 15, 2025 | Jul 11, 2025 |
| 4 | Insider transaction | Jul 15, 2025 | Jul 11, 2025 |
| 4 | Insider transaction | Jul 15, 2025 | Jul 11, 2025 |
| 4 | Insider transaction | Jul 15, 2025 | Jul 11, 2025 |
| 4 | Insider transaction | Jul 15, 2025 | Jul 11, 2025 |
| 4 | Insider transaction | Jul 15, 2025 | Jul 11, 2025 |
| 11-K | Employee savings plan report | Jun 24, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Shareholder vote results
|
May 20, 2025 | May 16, 2025 |
| 8-K |
Current report
Other events
|
May 19, 2025 | May 13, 2025 |
| 8-K |
Current report
Material agreement, New debt, Unregistered share sale, Other events
|
May 15, 2025 | May 12, 2025 |
| 8-K |
Current report
Material agreement
|
May 9, 2025 | May 9, 2025 |
| 424B5 | Prospectus supplement | May 9, 2025 | — |
| 10-Q | Quarterly report | May 9, 2025 | Mar 31, 2025 |
| 8-K |
Current report
Results of operations
|
May 9, 2025 | May 8, 2025 |
| PX14A6G | Filing | May 8, 2025 | — |
| 4 | Insider transaction | Apr 16, 2025 | Apr 15, 2025 |
| 3 | Initial insider ownership | Apr 16, 2025 | Apr 7, 2025 |
| 4 | Insider transaction | Apr 15, 2025 | Apr 11, 2025 |
| 4 | Insider transaction | Apr 15, 2025 | Apr 11, 2025 |
| 4 | Insider transaction | Apr 15, 2025 | Apr 11, 2025 |
| 4 | Insider transaction | Apr 15, 2025 | Apr 11, 2025 |
| 4 | Insider transaction | Apr 15, 2025 | Apr 11, 2025 |
| 4 | Insider transaction | Apr 15, 2025 | Apr 11, 2025 |
| ARS | Annual report to shareholders | Apr 1, 2025 | Dec 31, 2024 |
| DEFA14A | Additional proxy material | Apr 1, 2025 | — |
| DEF 14A | Proxy statement | Apr 1, 2025 | May 16, 2025 |
| 3 | Initial insider ownership | Mar 12, 2025 | Mar 2, 2025 |
| 8-K |
Current report
Officer or director change
|
Mar 10, 2025 | Mar 7, 2025 |
| 8-K |
Current report
Material agreement, New debt
|
Mar 3, 2025 | Mar 3, 2025 |
| 4 | Insider transaction | Feb 24, 2025 | Feb 20, 2025 |
| 4 | Insider transaction | Feb 24, 2025 | Feb 20, 2025 |
| 4 | Insider transaction | Feb 24, 2025 | Feb 20, 2025 |
| 4 | Insider transaction | Feb 24, 2025 | Feb 20, 2025 |
| 4 | Insider transaction | Feb 24, 2025 | Feb 20, 2025 |
| 4 | Insider transaction | Feb 24, 2025 | Feb 20, 2025 |
| 4 | Insider transaction | Feb 24, 2025 | Feb 20, 2025 |
| 10-K | Annual report | Feb 21, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Results of operations
|
Feb 21, 2025 | Feb 20, 2025 |
| 8-K |
Current report
Officer or director change
|
Feb 11, 2025 | Feb 7, 2025 |
| 4 | Insider transaction | Jan 14, 2025 | Jan 10, 2025 |
| 4 | Insider transaction | Jan 14, 2025 | Jan 10, 2025 |
| 4 | Insider transaction | Jan 14, 2025 | Jan 10, 2025 |
| 4 | Insider transaction | Jan 14, 2025 | Jan 10, 2025 |
| 4 | Insider transaction | Jan 14, 2025 | Jan 10, 2025 |
| 4 | Insider transaction | Jan 14, 2025 | Jan 10, 2025 |
| 8-K |
Current report
New debt
|
Dec 18, 2024 | Dec 18, 2024 |
| 4 | Insider transaction | Nov 20, 2024 | Nov 20, 2024 |
| 10-Q | Quarterly report | Nov 1, 2024 | Sep 30, 2024 |
| 8-K |
Current report
Results of operations
|
Nov 1, 2024 | Oct 31, 2024 |
| SC 13G/A | Amended ownership over 5% (passive) | Oct 16, 2024 | — |
| 4 | Insider transaction | Oct 15, 2024 | Oct 11, 2024 |
| 4 | Insider transaction | Oct 15, 2024 | Oct 11, 2024 |
| 4 | Insider transaction | Oct 15, 2024 | Oct 11, 2024 |
| 4 | Insider transaction | Oct 15, 2024 | Oct 11, 2024 |
| 4 | Insider transaction | Oct 15, 2024 | Oct 11, 2024 |
| 4 | Insider transaction | Oct 15, 2024 | Oct 11, 2024 |
| 4 | Insider transaction | Oct 15, 2024 | Oct 11, 2024 |
| 8-K |
Current report
Other events
|
Sep 6, 2024 | Sep 4, 2024 |
| 10-Q | Quarterly report | Aug 2, 2024 | Jun 30, 2024 |
| 8-K |
Current report
Results of operations
|
Aug 2, 2024 | Aug 1, 2024 |
| 8-K | Current report | Jul 26, 2024 | Jul 22, 2024 |
| 4 | Insider transaction | Jul 16, 2024 | Jul 12, 2024 |
| 4 | Insider transaction | Jul 16, 2024 | Jul 12, 2024 |
| 4 | Insider transaction | Jul 16, 2024 | Jul 12, 2024 |
| 4 | Insider transaction | Jul 16, 2024 | Jul 12, 2024 |
| 4 | Insider transaction | Jul 16, 2024 | Jul 12, 2024 |
| 4 | Insider transaction | Jul 16, 2024 | Jul 12, 2024 |
| 4 | Insider transaction | Jul 16, 2024 | Jul 12, 2024 |
| 8-K |
Current report
Officer or director change
|
Jul 15, 2024 | Jul 10, 2024 |
| 8-K |
Current report
Impairment
|
Jun 24, 2024 | Jun 20, 2024 |
| 11-K | Employee savings plan report | Jun 20, 2024 | Dec 31, 2023 |
| 8-K |
Current report
Material agreement, New debt, Other events
|
Jun 6, 2024 | Jun 3, 2024 |
| 8-K |
Current report
Shareholder vote results
|
May 20, 2024 | May 17, 2024 |
| 4 | Insider transaction | May 9, 2024 | May 7, 2024 |
| 4 | Insider transaction | May 9, 2024 | May 7, 2024 |
| 3 | Initial insider ownership | May 9, 2024 | May 1, 2024 |
| 10-Q | Quarterly report | May 3, 2024 | Mar 31, 2024 |
| 8-K |
Current report
Results of operations
|
May 3, 2024 | May 2, 2024 |
| 4 | Insider transaction | Apr 16, 2024 | Apr 12, 2024 |
| 4 | Insider transaction | Apr 16, 2024 | Apr 12, 2024 |
| 4 | Insider transaction | Apr 16, 2024 | Apr 12, 2024 |
| 4 | Insider transaction | Apr 16, 2024 | Apr 12, 2024 |
| 4 | Insider transaction | Apr 16, 2024 | Apr 12, 2024 |
| 4 | Insider transaction | Apr 16, 2024 | Apr 12, 2024 |
| ARS | Annual report to shareholders | Apr 2, 2024 | Dec 31, 2023 |
| DEFA14A | Additional proxy material | Apr 2, 2024 | — |
| DEF 14A | Proxy statement | Apr 2, 2024 | May 17, 2024 |
| 3 | Initial insider ownership | Apr 1, 2024 | Apr 1, 2024 |
| 8-K |
Current report
Officer or director change
|
Mar 8, 2024 | Mar 7, 2024 |
| 8-K |
Current report
Other events
|
Mar 7, 2024 | Mar 4, 2024 |
| 8-K |
Current report
Material agreement, New debt
|
Mar 5, 2024 | Mar 1, 2024 |
| 4 | Insider transaction | Feb 20, 2024 | Feb 15, 2024 |
| 4 | Insider transaction | Feb 20, 2024 | Feb 15, 2024 |
| 4 | Insider transaction | Feb 20, 2024 | Feb 15, 2024 |
| 4 | Insider transaction | Feb 20, 2024 | Feb 15, 2024 |
| 4 | Insider transaction | Feb 20, 2024 | Feb 15, 2024 |
| 4 | Insider transaction | Feb 20, 2024 | Feb 15, 2024 |
| 4 | Insider transaction | Feb 20, 2024 | Feb 15, 2024 |
| 10-K | Annual report | Feb 16, 2024 | Dec 31, 2023 |
| 8-K |
Current report
Results of operations
|
Feb 16, 2024 | Feb 15, 2024 |
| 8-K |
Current report
Officer or director change
|
Feb 13, 2024 | Feb 8, 2024 |
| SC 13G/A | Amended ownership over 5% (passive) | Feb 13, 2024 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Jan 30, 2024 | — |
| SC 13G/A | Amended ownership over 5% (passive) | Jan 24, 2024 | — |
| 4 | Insider transaction | Jan 17, 2024 | Jan 12, 2024 |
| 4 | Insider transaction | Jan 17, 2024 | Jan 12, 2024 |
| 4 | Insider transaction | Jan 17, 2024 | Jan 12, 2024 |
| 4 | Insider transaction | Jan 17, 2024 | Jan 12, 2024 |
| 4 | Insider transaction | Jan 17, 2024 | Jan 12, 2024 |
| 4 | Insider transaction | Jan 17, 2024 | Jan 12, 2024 |
Showing 200 filings, the most recent 200. Main filings leave out insider and ownership forms such as Form 4; choose a type above to see them. Each form opens on SEC.gov. Older filings are on SEC EDGAR.
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Company profile
- Industry
- Electric & Other Services Combined (SIC 4931)
- Listed as
- LNT (Nasdaq)
- Fiscal year ends
- December 31
- Incorporated in
- WI
- Headquarters
- Madison, WI
- SEC filer status
- Large accelerated filer
- SEC CIK
- 352541
- Former names
- ALLIANT ENERGY CORP (until Oct 30, 2026); INTERSTATE ENERGY CORP (until May 13, 1999); WPL HOLDINGS INC (until Feb 23, 1998)
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.