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 |
|---|---|---|---|
| 424B5 | Prospectus supplement | Mar 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 | — |
| 424B5 | Prospectus supplement | Sep 25, 2025 | — |
| FWP | Free writing prospectus | Sep 23, 2025 | — |
| 424B5 | Prospectus supplement | Sep 23, 2025 | — |
| 424B5 | Prospectus supplement | May 9, 2025 | — |
| S-3ASR | Automatic shelf registration | Dec 15, 2023 | — |
| S-3ASR | Automatic shelf registration | Nov 6, 2023 | — |
| 424B5 | Prospectus supplement | Dec 15, 2022 | — |
| S-3ASR | Automatic shelf registration | Dec 15, 2020 | — |
| S-3ASR | Automatic shelf registration | Nov 6, 2020 | — |
| S-8 | Employee stock plan registration | May 26, 2020 | — |
| 424B2 | Prospectus | Nov 15, 2019 | — |
| 424B5 | Prospectus supplement | Nov 14, 2019 | — |
| S-8 | Employee stock plan registration | Mar 15, 2019 | — |
| 424B2 | Prospectus | Dec 14, 2018 | — |
| 424B5 | Prospectus supplement | Dec 13, 2018 | — |
| 424B5 | Prospectus supplement | May 21, 2018 | — |
| S-3ASR | Automatic shelf registration | Dec 15, 2017 | — |
| S-3ASR | Automatic shelf registration | Nov 6, 2017 | — |
| 424B5 | Prospectus supplement | May 9, 2017 | — |
| S-8 | Employee stock plan registration | May 5, 2016 | — |
| S-8 POS | Form s-8 pos | May 5, 2016 | — |
| S-8 POS | Form s-8 pos | May 5, 2016 | — |
| 424B5 | Prospectus supplement | Mar 4, 2015 | — |
| S-3ASR | Automatic shelf registration | Dec 15, 2014 | — |
| S-3ASR | Automatic shelf registration | Nov 10, 2014 | — |
Showing 33 filings. 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.