When did American Tower Corp file this DEFA14A?

American Tower Corp (AMT) filed this Additional Proxy Materials (DEFA14A) with the SEC on April 8, 2026. The accession number assigned by EDGAR is 0001053507-26-000090.

What does a DEFA14A disclose?

DEFA14A is additional definitive proxy soliciting material filed in connection with a shareholder meeting — supplemental letters, slides, or amendments issued after the main proxy statement.

What is the key takeaway from this filing?

Consult the filing for more details. This is Boardroom Alpha's one-line summary of the additional proxy materials; see the full filing text above for the formal disclosure.

Where can I find American Tower Corp's prior proxy statements on EDGAR?

The SEC EDGAR browser lists every DEFA14A American Tower Corp has filed under CIK 1053507, sortable by date. Use the "View on SEC EDGAR" link in the page header, or browse directly via https://www.sec.gov/cgi-bin/browse-edgar.

Boardroom Alpha

AMT · Additional Proxy Materials (DEFA14A) · Filed April 8, 2026

American Tower Corp — Additional Proxy Materials (DEFA14A)

Form

DEFA14A

Filed

April 8, 2026

Ticker

AMT

Accession

0001053507-26-000090

American Tower Corp on Boardroom Alpha View on SEC EDGAR

Boardroom Alpha · Filing insights

Consult the filing for more details.

About American Tower Corp

Market cap

$86.4B

1Y TSR

−13.7%

3Y TSR

+1.7%

Board grade

Sector

Real Estate

CEO

Steven O Vondran

Last annual meeting: May 20, 2026 · View full American Tower Corp profile →

Document

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

(Rule 14a-101)

INFORMATION REQUIRED IN PROXY STATEMENT

SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

(Amendment No. )

Filed by the Registrant x Filed by a Party other than the Registrant ☐

Check the appropriate box:


☐			Preliminary Proxy Statement.

☐			Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)).

☐			Definitive Proxy Statement.

x			Definitive Additional Materials.

☐			Soliciting Material Pursuant to §240.14a-12.
AMERICAN TOWER CORPORATION
(Name of Registrant as Specified in its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check the appropriate box):

x			No fee required.

☐			Fee paid previously with preliminary materials.

☐			Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11.

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More filings

Other filings from American Tower Corp (AMT)

8-KCurrent Report
Jun 2, 2026
8-KCurrent Report
May 27, 2026
8-KCurrent Report
May 21, 2026
8-KCurrent Report
May 19, 2026
8-KCurrent Report
May 7, 2026
DEFA14AAdditional Proxy Materials
Apr 28, 2026
10-QQuarterly Report
Apr 28, 2026
8-KCurrent Report
Apr 28, 2026
DEF 14AProxy Statement
Apr 8, 2026
8-KCurrent Report
Mar 10, 2026
8-KCurrent Report
Mar 5, 2026
8-KCurrent Report
Feb 27, 2026

Continue researching

Reference

Frequently asked questions

When did American Tower Corp file this DEFA14A?: American Tower Corp (AMT) filed this Additional Proxy Materials (DEFA14A) with the SEC on April 8, 2026. The accession number assigned by EDGAR is 0001053507-26-000090.
What does a DEFA14A disclose?: DEFA14A is additional definitive proxy soliciting material filed in connection with a shareholder meeting — supplemental letters, slides, or amendments issued after the main proxy statement.
What is the key takeaway from this filing?: Consult the filing for more details. This is Boardroom Alpha's one-line summary of the additional proxy materials; see the full filing text above for the formal disclosure.
Where can I find American Tower Corp's prior proxy statements on EDGAR?: The SEC EDGAR browser lists every DEFA14A American Tower Corp has filed under CIK 1053507, sortable by date. Use the "View on SEC EDGAR" link in the page header, or browse directly via https://www.sec.gov/cgi-bin/browse-edgar.

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