American Superconductor Corp /DE/ SEC filings AMSC
American Superconductor Corp /DE/ has 1,003 filings in SEC EDGAR's recent list, going back to Jan 31, 2008. Its latest annual report, Form ARS, was filed on Jun 18, 2026 for the period ended Mar 31, 2026. The latest quarterly report (Form 10-Q) was filed on Nov 4, 2026, covering the quarter ended Sep 30, 2026. The most recent current report (Form 8-K) was filed on Nov 4, 2026 (results of operations). The company's fiscal year ends on March 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| DEFA14A | Additional proxy material | Jun 18, 2026 | — |
| DEF 14A | Proxy statement | Jun 18, 2026 | Jul 31, 2026 |
| DEFA14A | Additional proxy material | Jun 13, 2025 | — |
| DEF 14A | Proxy statement | Jun 13, 2025 | Jul 25, 2025 |
| DEFA14A | Additional proxy material | Jun 20, 2024 | — |
| DEF 14A | Proxy statement | Jun 20, 2024 | Aug 2, 2024 |
| PRE 14A | Preliminary proxy statement | Jun 10, 2024 | Aug 2, 2024 |
| DEFA14A | Additional proxy material | Jun 28, 2023 | — |
| DEF 14A | Proxy statement | Jun 28, 2023 | Aug 11, 2023 |
| DEFA14A | Additional proxy material | Jul 26, 2022 | — |
| DEFA14A | Additional proxy material | Jun 23, 2022 | — |
| DEF 14A | Proxy statement | Jun 23, 2022 | Aug 2, 2022 |
| DEFA14A | Additional proxy material | Jun 17, 2021 | — |
| DEF 14A | Proxy statement | Jun 17, 2021 | Jul 30, 2021 |
| DEFA14A | Additional proxy material | Jun 19, 2020 | — |
| DEF 14A | Proxy statement | Jun 19, 2020 | Jul 31, 2020 |
| DEFA14A | Additional proxy material | Jun 20, 2019 | — |
| DEF 14A | Proxy statement | Jun 20, 2019 | Aug 1, 2019 |
| DEFA14A | Additional proxy material | Jun 15, 2018 | — |
| DEF 14A | Proxy statement | Jun 15, 2018 | Jul 27, 2018 |
| DEFA14A | Additional proxy material | Jun 16, 2017 | — |
| DEF 14A | Proxy statement | Jun 16, 2017 | Jul 27, 2017 |
| DEFA14A | Additional proxy material | Jun 17, 2016 | — |
| DEF 14A | Proxy statement | Jun 17, 2016 | Jul 29, 2016 |
| DEFA14A | Additional proxy material | Jun 19, 2015 | — |
| DEF 14A | Proxy statement | Jun 19, 2015 | Jul 31, 2015 |
| DEFA14A | Additional proxy material | Feb 6, 2015 | — |
| DEF 14A | Proxy statement | Feb 6, 2015 | Mar 18, 2015 |
| PRE 14A | Preliminary proxy statement | Jan 21, 2015 | Mar 18, 2015 |
| DEFA14A | Additional proxy material | Jun 18, 2014 | — |
| DEF 14A | Proxy statement | Jun 18, 2014 | Aug 1, 2014 |
| DEFA14A | Additional proxy material | Jun 18, 2013 | — |
| DEF 14A | Proxy statement | Jun 18, 2013 | Aug 1, 2013 |
| DEF 14A | Proxy statement | Jun 26, 2012 | Jul 27, 2012 |
| PRE 14A | Preliminary proxy statement | Jun 14, 2012 | Jul 27, 2012 |
| DEF 14A | Proxy statement | Nov 4, 2011 | Dec 8, 2011 |
| PRE 14A | Preliminary proxy statement | Oct 25, 2011 | Dec 8, 2011 |
| DEFA14A | Additional proxy material | Jun 22, 2010 | — |
| DEF 14A | Proxy statement | Jun 22, 2010 | Aug 6, 2010 |
| DEFA14A | Additional proxy material | Jun 23, 2009 | — |
| DEF 14A | Proxy statement | Jun 22, 2009 | Aug 6, 2009 |
| DEFA14A | Additional proxy material | Jun 24, 2008 | — |
| DEF 14A | Proxy statement | Jun 23, 2008 | Aug 7, 2008 |
Showing 43 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
- Motors & Generators (SIC 3621)
- Listed as
- AMSC (Nasdaq)
- Fiscal year ends
- March 31
- Incorporated in
- DE
- Headquarters
- Devens, MA
- SEC filer status
- Large accelerated filer
- SEC CIK
- 880807
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.