American Tower (AMT) EVP receives RSU grant and uses shares for tax withholding

Rhea-AI Filing Summary

American Tower (AMT) executive Ruth T. Dowling reported routine equity compensation activity. On March 10, 2026, she acquired 6,878 shares of Common Stock as a grant of restricted stock units (RSUs) under the 2007 Equity Incentive Plan. These RSUs vest in three equal annual installments starting one year from the grant date, with each RSU representing the right to receive one share of Common Stock.

Also on March 10 and March 11, 2026, a total of 7,492 shares of Common Stock were delivered back to the company to cover withholding taxes upon vesting of previously granted RSUs and performance-based restricted stock units. These tax-withholding dispositions are not open-market sales. After these transactions, Dowling directly owned 30,433 shares of Common Stock.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Dowling Ruth T

(Last) (First) (Middle)

222 BERKELEY STREET

(Street)

BOSTON MA 02116

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
AMERICAN TOWER CORP /MA/ [ AMT ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, Chief Admin Ofr, GC & Sec

3. Date of Earliest Transaction (Month/Day/Year)
03/10/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	03/10/2026		A		6,878(1)	A	$0	37,925	D
Common Stock	03/10/2026		F(2)		6,629	D	$186.12	31,296	D
Common Stock	03/11/2026		F(3)		863	D	$182.85	30,433	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. These restricted stock units ("RSUs") were granted pursuant to the 2007 Equity Incentive Plan, as amended (the "Plan"), and vest 1/3rd annually over three years, commencing one year from the date of grant. Each RSU represents a contingent right to receive one share of Common Stock.

2. Shares delivered to the issuer for the payment of withholding taxes in connection with the vesting of RSUs and performance-based restricted stock units previously granted under the Plan.

3. Shares delivered to the issuer for the payment of withholding taxes in connection with the vesting of RSUs previously granted under the Plan.

Remarks:

	/s/ Marina A. Breed, as attorney-in-fact	03/12/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What insider transactions did AMT executive Ruth Dowling report on this Form 4?

Ruth T. Dowling reported receiving 6,878 shares of AMT Common Stock as a restricted stock unit grant and delivering 7,492 shares back to American Tower to cover tax withholding obligations from vesting awards, leaving her with 30,433 directly owned shares after the latest transaction.

Were any of Ruth Dowling’s AMT share transactions open-market buys or sells?

No, none of the reported transactions were open-market trades. The Form 4 shows one equity grant and two dispositions coded as tax-withholding events, where shares were delivered to American Tower to satisfy withholding taxes tied to vesting RSUs and performance-based awards.

How many AMT shares did Ruth Dowling receive as a new equity grant?

She received 6,878 shares of AMT Common Stock through a restricted stock unit grant. These RSUs were issued under the company’s 2007 Equity Incentive Plan and vest in three equal annual installments beginning one year after the grant date, subject to continued service conditions.

Why did Ruth Dowling dispose of AMT shares in this Form 4 filing?

She disposed of shares solely to cover tax withholding obligations. A total of 7,492 AMT shares were delivered back to the issuer in connection with the vesting of previously granted restricted stock units and performance-based restricted stock units, as described in the Form 4 footnotes.

What are the vesting terms of Ruth Dowling’s new AMT RSU grant?

The new RSU grant vests one-third each year over three years. Vesting begins one year from the grant date, and each vested restricted stock unit converts into one share of AMT Common Stock, consistent with the terms of the 2007 Equity Incentive Plan.

How many AMT shares does Ruth Dowling own after these transactions?

After the reported grant and tax-withholding dispositions, Ruth T. Dowling directly owns 30,433 shares of AMT Common Stock. This figure reflects her position following the most recent transaction date disclosed in the Form 4 insider trading report.