(AMT)

Role: EVP, CFO & Treasurer
Signature: /s/ Marina A. Breed, as attorney-in-fact
Stock symbol: AMT
Transactions as of: Aug 17, 2023
Transactions value $: -$969,568
Form type: 4
Date filed: 8/21/2023, 05:10 PM
Previous filing: Aug 14, 2023
Next filing: Mar 1, 2024

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
transaction	AMT	Common Stock	Options Exercise	$812K	+10K	+19.74%	$81.18	60.7K	Aug 17, 2023	Direct
transaction	AMT	Common Stock	Sale	-$1.71M	-9.6K	-15.83%	$178.11	51.1K	Aug 17, 2023	Direct	F1, F2
transaction	AMT	Common Stock	Sale	-$71.5K	-400	-0.78%	$178.78	50.7K	Aug 17, 2023	Direct	F1, F3

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	AMT	Option to Purchase Common Stock	Options Exercise	$0	-10K	-30.29%	$0.00	23K	Aug 17, 2023	Common Stock	10K	$81.18	Direct	F4

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Buy Plan / Sale Plan: These are also open market purchases/sales of shares, but in this case the transaction is part of a trading plan. Rule 10b5-1 allows insiders to setup a trading plan to buy/sell stocks over a certain period of time. Since the purchases/sales are predetermined, this protects the insiders from violating insider trading law.

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).

Explanation of Responses:

Id	Content
F1	The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on April 27, 2023.
F2	Represents the weighted average price of shares sold in multiple same-day transactions at prices ranging from $177.64 to $178.58 per share.
F3	Represents the weighted average price of shares sold in multiple same-day transactions at prices ranging from $178.74 to $178.88 per share.
F4	This option was granted pursuant to the 2007 Equity Incentive Plan, as amended, and is exercisable in 25% cumulative annual increments beginning March 10, 2015.