Quick Answer: T-Mobile US, Inc. is an American wireless network operator headquartered in Bellevue, Washington. Its majority shareholder and namesake is the German telecommunications company Deutsche Telekom. T-Mobile is the second largest wireless carrier in the United States, with 140 million subscribers as of September 30, 2025. The company was founded in 1994 by John W. Stanton of the Western Wireless Corporation as VoiceStream Wireless. Deutsche Telekom then gained plurality ownership in 2001 and renamed it after its global T-Mobile brand. As of April 2023, the German company holds a 51.4% stake in the company. T-Mobile offers services under the primary retail brands T-Mobile and Metro by T-Mobile. In 2020, T-Mobile expanded through the acquisition of Sprint, which also made T-Mobile the operator of Assurance Wireless, a service subsidized by the federal Lifeline program.