144 0000946770 XXXXXXXX LIVE 0001283699 T-Mobile US, Inc. 001-33409 12920 SE 38TH STREET BELLEVUE WA 98006 800-318-9270 Deutsche Telekom AG 10% Stockholder Common Stock Santander US Capital Markets LLC

437 Madison Avenue New York NY 10022

400000 78692000 1118506626 12/22/2025 NASDAQ Common Stock 05/31/2001 Merger or Acquisition Issuer N 400000 05/31/2001 Not Applicable N 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 09/22/2025 64426 15317436.12 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 09/23/2025 64426 15359654.48 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 09/24/2025 64426 15357818.34 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 09/25/2025 64426 15396564.14 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 09/26/2025 64426 15341074.02 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 09/29/2025 64426 15340655.25 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 09/30/2025 64426 15432571.83 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/01/2025 64426 15102852.44 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/02/2025 64426 14844465.53 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/03/2025 64426 14767019.03 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/06/2025 64426 14469866.99 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/07/2025 64426 14644757.81 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/08/2025 64426 14571093.13 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/09/2025 64426 14598738.32 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/10/2025 64426 14716103.17 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/13/2025 64426 14570171.83 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/14/2025 64426 14756659.33 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/15/2025 64426 14672828.22 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/16/2025 64426 14626151.59 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/17/2025 64426 14726050.54 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/20/2025 64426 14743761.25 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/21/2025 64426 14770369.19 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/22/2025 64426 14571544.11 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/23/2025 37721 7678323.46 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/24/2025 856 188341.74 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/27/2025 64426 14218064.42 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/28/2025 53507 11812547.76 10b5-1 Sales for Deutsche Telekom Holding B.V.

Stationsplein 8K Maastricht P7 6221 BT

Common Stock 10/29/2025 1374 302910.94 Deutsche Telekom Holding B.V. ("DT Holding"), an indirect wholly-owned subsidiary of Deutsche Telekom AG, holds the shares to be sold. On June 12, 2025, DT Holding entered into a Rule 10b5-1 trading plan with Santander US Capital Markets LLC (the "Santander Plan"), which contemplates sales of up to 5,000,000 shares of Common Stock. Aggregate Market Value of shares is calculated based on a closing share price of $196.73 on December 19, 2025. Any sales by the reporting person will occur under the terms of the Santander Plan, which contemplates sales of the Common Stock from September 11, 2025, through December 30, 2025, under the parameters set forth in such trading plan. 12/22/2025 06/12/2025 /s/ Christoph Appel, Christoph Appel, Attorney-in-fact