American Tower Corp /MA/ SEC filings AMT
American Tower Corp /MA/ has 1,001 filings in SEC EDGAR's recent list, going back to May 22, 2017. Its latest annual report, Form ARS, was filed on Apr 8, 2026 for the period ended Dec 31, 2025. The latest quarterly report (Form 10-Q) was filed on Oct 27, 2026, covering the quarter ended Sep 30, 2026. The most recent current report (Form 8-K) was filed on Oct 27, 2026 (results of operations). The company's fiscal year ends on December 31.
| Form | Description | Filed | Period |
|---|---|---|---|
| 4 | Insider transaction | Nov 3, 2026 | Oct 30, 2026 |
| 4 | Insider transaction | Oct 30, 2026 | Oct 28, 2026 |
| 144 | Notice of proposed sale | Oct 30, 2026 | — |
| 144 | Notice of proposed sale | Oct 28, 2026 | — |
| 10-Q | Quarterly report | Oct 27, 2026 | Sep 30, 2026 |
| 8-K |
Current report
Results of operations
|
Oct 27, 2026 | Oct 27, 2026 |
| 4 | Insider transaction | Oct 22, 2026 | Apr 28, 2023 |
| 4 | Insider transaction | Oct 5, 2026 | Oct 1, 2026 |
| 3 | Initial insider ownership | Sep 23, 2026 | Sep 17, 2026 |
| 8-K |
Current report
Officer or director change, Other events
|
Sep 18, 2026 | Sep 17, 2026 |
| 8-K |
Current report
Material agreement, New debt
|
Sep 14, 2026 | Sep 14, 2026 |
| 424B2 | Prospectus | Sep 10, 2026 | — |
| 8-K |
Current report
Other events
|
Sep 9, 2026 | Sep 9, 2026 |
| FWP | Free writing prospectus | Sep 9, 2026 | — |
| 424B5 | Prospectus supplement | Sep 9, 2026 | — |
| 4 | Insider transaction | Aug 25, 2026 | Aug 21, 2026 |
| 4 | Insider transaction | Jul 31, 2026 | Jul 29, 2026 |
| 4 | Insider transaction | Jul 30, 2026 | Jul 28, 2026 |
| 144 | Notice of proposed sale | Jul 29, 2026 | — |
| 144 | Notice of proposed sale | Jul 28, 2026 | — |
| 10-Q | Quarterly report | Jul 28, 2026 | Jun 30, 2026 |
| 8-K |
Current report
Results of operations
|
Jul 28, 2026 | Jul 28, 2026 |
| CERT | Nyse certification | Jun 8, 2026 | — |
| 8-K |
Current report
Other events
|
Jun 4, 2026 | Jun 2, 2026 |
| 4 | Insider transaction | Jun 3, 2026 | Jun 1, 2026 |
| 8-K |
Current report
Other events
|
Jun 2, 2026 | Jun 2, 2026 |
| 4 | Insider transaction | Jun 1, 2026 | May 28, 2026 |
| 8-A12B | Filing | May 27, 2026 | — |
| 8-K |
Current report
Material agreement, New debt
|
May 27, 2026 | May 27, 2026 |
| S-8 | Employee stock plan registration | May 26, 2026 | — |
| 25-NSE | Delisting notice | May 22, 2026 | — |
| 8-K |
Current report
Officer or director change, Shareholder vote results, Other events
|
May 21, 2026 | May 20, 2026 |
| 424B2 | Prospectus | May 20, 2026 | — |
| 4 | Insider transaction | May 20, 2026 | May 20, 2026 |
| 8-K |
Current report
Other events
|
May 19, 2026 | May 19, 2026 |
| FWP | Free writing prospectus | May 19, 2026 | — |
| 424B5 | Prospectus supplement | May 19, 2026 | — |
| 8-K |
Current report
Material agreement, New debt
|
May 7, 2026 | May 7, 2026 |
| 4 | Insider transaction | Apr 30, 2026 | Apr 28, 2026 |
| 3 | Initial insider ownership | Apr 30, 2026 | Apr 27, 2026 |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 29, 2026 | — |
| DEFA14A | Additional proxy material | Apr 28, 2026 | — |
| 10-Q | Quarterly report | Apr 28, 2026 | Mar 31, 2026 |
| SCHEDULE 13G | Ownership over 5% (passive) | Apr 28, 2026 | — |
| 8-K |
Current report
Results of operations
|
Apr 28, 2026 | Apr 28, 2026 |
| ARS | Annual report to shareholders | Apr 8, 2026 | Dec 31, 2025 |
| DEFA14A | Additional proxy material | Apr 8, 2026 | — |
| DEF 14A | Proxy statement | Apr 8, 2026 | May 20, 2026 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Mar 26, 2026 | — |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 4 | Insider transaction | Mar 12, 2026 | Mar 10, 2026 |
| 8-K |
Current report
Officer or director change
|
Mar 10, 2026 | Mar 6, 2026 |
| 4 | Insider transaction | Mar 6, 2026 | Mar 4, 2026 |
| 4 | Insider transaction | Mar 6, 2026 | Mar 4, 2026 |
| 8-K |
Current report
Other events
|
Mar 5, 2026 | Mar 5, 2026 |
| 4 | Insider transaction | Mar 4, 2026 | Mar 2, 2026 |
| 144 | Notice of proposed sale | Mar 4, 2026 | — |
| 4 | Insider transaction | Mar 3, 2026 | Feb 27, 2026 |
| 4 | Insider transaction | Mar 3, 2026 | Feb 27, 2026 |
| 144 | Notice of proposed sale | Mar 2, 2026 | — |
| 144 | Notice of proposed sale | Feb 27, 2026 | — |
| 144 | Notice of proposed sale | Feb 27, 2026 | — |
| 8-K |
Current report
Officer or director change
|
Feb 27, 2026 | Feb 25, 2026 |
| 4 | Insider transaction | Feb 27, 2026 | Feb 25, 2026 |
| 4 | Insider transaction | Feb 27, 2026 | Feb 25, 2026 |
| 4 | Insider transaction | Feb 27, 2026 | Feb 25, 2026 |
| 144 | Notice of proposed sale | Feb 25, 2026 | — |
| 10-K | Annual report | Feb 24, 2026 | Dec 31, 2025 |
| 8-K |
Current report
Results of operations
|
Feb 24, 2026 | Feb 24, 2026 |
| 4 | Insider transaction | Feb 19, 2026 | Feb 17, 2026 |
| 144 | Notice of proposed sale | Feb 17, 2026 | — |
| 8-K |
Current report
Officer or director change
|
Jan 29, 2026 | Jan 26, 2026 |
| 8-K |
Current report
Other events
|
Jan 28, 2026 | Jan 28, 2026 |
| 4 | Insider transaction | Jan 6, 2026 | Jan 3, 2026 |
| 4 | Insider transaction | Jan 6, 2026 | Jan 2, 2026 |
| 4 | Insider transaction | Dec 11, 2025 | Dec 9, 2025 |
| SCHEDULE 13D/A | Amended ownership over 5% (active) | Dec 11, 2025 | — |
| 144 | Notice of proposed sale | Dec 9, 2025 | — |
| 8-K |
Current report
Material agreement, New debt
|
Dec 5, 2025 | Dec 5, 2025 |
| 8-K |
Current report
Other events
|
Dec 4, 2025 | Dec 4, 2025 |
| 424B2 | Prospectus | Dec 3, 2025 | — |
| 8-K |
Current report
Other events
|
Dec 2, 2025 | Dec 2, 2025 |
| FWP | Free writing prospectus | Dec 2, 2025 | — |
| 424B5 | Prospectus supplement | Dec 2, 2025 | — |
| 8-K |
Current report
Officer or director change
|
Nov 7, 2025 | Nov 5, 2025 |
| 4 | Insider transaction | Nov 4, 2025 | Oct 31, 2025 |
| 10-Q | Quarterly report | Oct 28, 2025 | Sep 30, 2025 |
| 8-K |
Current report
Results of operations
|
Oct 28, 2025 | Oct 28, 2025 |
| 4 | Insider transaction | Oct 3, 2025 | Oct 1, 2025 |
| 8-K |
Current report
Regulation FD disclosure
|
Sep 24, 2025 | Sep 23, 2025 |
| 4 | Insider transaction | Sep 23, 2025 | Sep 19, 2025 |
| 8-K |
Current report
Officer or director change, Other events
|
Sep 18, 2025 | Sep 16, 2025 |
| 8-K |
Current report
Material agreement, New debt
|
Sep 16, 2025 | Sep 16, 2025 |
| 424B2 | Prospectus | Sep 12, 2025 | — |
| 8-K |
Current report
Other events
|
Sep 11, 2025 | Sep 11, 2025 |
| FWP | Free writing prospectus | Sep 11, 2025 | — |
| 424B5 | Prospectus supplement | Sep 11, 2025 | — |
| 8-K |
Current report
Regulation FD disclosure
|
Sep 5, 2025 | Sep 3, 2025 |
| 3 | Initial insider ownership | Aug 29, 2025 | Aug 22, 2025 |
| 8-K |
Current report
Officer or director change
|
Aug 25, 2025 | Aug 22, 2025 |
| 4 | Insider transaction | Aug 1, 2025 | Jul 31, 2025 |
| 144 | Notice of proposed sale | Jul 31, 2025 | — |
| 10-Q | Quarterly report | Jul 29, 2025 | Jun 30, 2025 |
| 8-K |
Current report
Results of operations
|
Jul 29, 2025 | Jul 29, 2025 |
| 4 | Insider transaction | Jun 3, 2025 | Jun 1, 2025 |
| CERT | Nyse certification | Jun 2, 2025 | — |
| S-3ASR | Automatic shelf registration | Jun 2, 2025 | — |
| 8-A12B | Filing | May 30, 2025 | — |
| 8-K |
Current report
Material agreement, New debt
|
May 30, 2025 | May 30, 2025 |
| 424B2 | Prospectus | May 22, 2025 | — |
| 8-K |
Current report
Other events
|
May 21, 2025 | May 21, 2025 |
| FWP | Free writing prospectus | May 21, 2025 | — |
| 424B5 | Prospectus supplement | May 21, 2025 | — |
| 4 | Insider transaction | May 16, 2025 | May 14, 2025 |
| 8-K |
Current report
Shareholder vote results, Other events
|
May 15, 2025 | May 14, 2025 |
| 10-Q | Quarterly report | Apr 29, 2025 | Mar 31, 2025 |
| 8-K |
Current report
Results of operations
|
Apr 29, 2025 | Apr 29, 2025 |
| 25-NSE | Delisting notice | Apr 4, 2025 | — |
| 4 | Insider transaction | Apr 2, 2025 | Mar 31, 2025 |
| ARS | Annual report to shareholders | Apr 2, 2025 | Dec 31, 2024 |
| DEFA14A | Additional proxy material | Apr 2, 2025 | — |
| DEF 14A | Proxy statement | Apr 2, 2025 | May 14, 2025 |
| 8-K |
Current report
Officer or director change
|
Mar 20, 2025 | Mar 17, 2025 |
| 4 | Insider transaction | Mar 19, 2025 | Mar 17, 2025 |
| 144 | Notice of proposed sale | Mar 17, 2025 | — |
| 8-K |
Current report
Material agreement, New debt
|
Mar 14, 2025 | Mar 14, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 4 | Insider transaction | Mar 12, 2025 | Mar 10, 2025 |
| 424B2 | Prospectus | Mar 12, 2025 | — |
| 8-K |
Current report
Other events
|
Mar 11, 2025 | Mar 11, 2025 |
| FWP | Free writing prospectus | Mar 11, 2025 | — |
| 424B5 | Prospectus supplement | Mar 11, 2025 | — |
| 8-K |
Current report
Other events
|
Mar 6, 2025 | Mar 6, 2025 |
| 8-K |
Current report
Officer or director change
|
Mar 5, 2025 | Feb 27, 2025 |
| 4 | Insider transaction | Mar 3, 2025 | Feb 27, 2025 |
| 4 | Insider transaction | Mar 3, 2025 | Feb 27, 2025 |
| 4 | Insider transaction | Mar 3, 2025 | Feb 27, 2025 |
| 4 | Insider transaction | Mar 3, 2025 | Feb 27, 2025 |
| 4 | Insider transaction | Feb 28, 2025 | Feb 26, 2025 |
| 4 | Insider transaction | Feb 28, 2025 | Feb 26, 2025 |
| 144 | Notice of proposed sale | Feb 27, 2025 | — |
| 144 | Notice of proposed sale | Feb 26, 2025 | — |
| 144 | Notice of proposed sale | Feb 26, 2025 | — |
| 10-K | Annual report | Feb 25, 2025 | Dec 31, 2024 |
| 8-K |
Current report
Results of operations
|
Feb 25, 2025 | Feb 25, 2025 |
| 4 | Insider transaction | Feb 18, 2025 | Feb 13, 2025 |
| 144 | Notice of proposed sale | Feb 13, 2025 | — |
| 3/A | Form 3/a | Feb 7, 2025 | Feb 5, 2025 |
| 3 | Initial insider ownership | Feb 6, 2025 | Feb 5, 2025 |
| 8-K |
Current report
Officer or director change
|
Feb 5, 2025 | Feb 5, 2025 |
| SCHEDULE 13G/A | Amended ownership over 5% (passive) | Feb 5, 2025 | — |
| 8-K |
Current report
Material agreement, New debt
|
Jan 28, 2025 | Jan 28, 2025 |
| 3 | Initial insider ownership | Jan 24, 2025 | Jan 13, 2025 |
| 4 | Insider transaction | Jan 17, 2025 | Jan 16, 2025 |
| 144 | Notice of proposed sale | Jan 16, 2025 | — |
| 4 | Insider transaction | Jan 7, 2025 | Jan 3, 2025 |
| 8-K |
Current report
Officer or director change, Bylaw or fiscal year change
|
Jan 7, 2025 | Jan 2, 2025 |
| 8-K |
Current report
Other events
|
Dec 5, 2024 | Dec 5, 2024 |
| 8-K |
Current report
Material agreement, New debt
|
Nov 21, 2024 | Nov 21, 2024 |
| 424B2 | Prospectus | Nov 19, 2024 | — |
| 8-K |
Current report
Other events
|
Nov 19, 2024 | Nov 18, 2024 |
| FWP | Free writing prospectus | Nov 19, 2024 | — |
| 424B5 | Prospectus supplement | Nov 18, 2024 | — |
| 8-K |
Current report
Officer or director change
|
Oct 31, 2024 | Oct 28, 2024 |
| 10-Q | Quarterly report | Oct 29, 2024 | Sep 30, 2024 |
| 8-K |
Current report
Results of operations
|
Oct 29, 2024 | Oct 29, 2024 |
| 4 | Insider transaction | Oct 3, 2024 | Oct 1, 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
- Real Estate Investment Trusts (SIC 6798)
- Listed as
- AMT (NYSE)
- Fiscal year ends
- December 31
- Incorporated in
- DE
- Headquarters
- Boston, MA
- SEC filer status
- Large accelerated filer
- SEC CIK
- 1053507
- Former names
- AMERICAN TOWER SYSTEMS CORP (until May 8, 1998)
Other Real Estate Investment Trusts companies
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- Public Storage PSA
- Realty Income Corp O
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Source: SEC EDGAR filings. This is company-reported data, not investment advice.