T-Mobile US Appointed Jonathan A. Freier As COO, Effective December 5, 2025.

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers.

Letter Agreement with Jonathan A. Freier

On December 5, 2025, T-Mobile US, Inc. ("T-Mobile," the "Company" or "us") appointed Jonathan A. Freier as the Chief Operating Officer ("COO") of T-Mobile, effective December 5, 2025.

Mr. Freier, age 50, has served as our President, Consumer Group since September 2021, leading consumer marketing, digital excellence, retail sales and distribution, customer care, strategic planning, and various operational functions across the enterprise. Mr. Freier has over 25 years of experience in the telecommunications industry, beginning in 1994 with Western Wireless, T-Mobile's predecessor company, which became T-Mobile in 2001. Mr. Freier holds a Bachelor of Science in organizational management from Lubbock Christian University and a Master of Science in organizational leadership from Colorado State University.

In connection with Mr. Freier's appointment as COO, on December 8, 2025, T-Mobile entered into a compensation letter agreement (the "Letter Agreement") with Mr. Freier, which provides for his continued employment with the Company. The material terms of the Letter Agreement are described below.