Former T-Mobile CEO Mike Sievert wraps up his run at the wireless giant

Mike Sievert in 2017 when he was serving as T-Mobile’s COO before rising to CEO in 2020. (GeekWire File Photo/Kevin Lisota) Former T-Mobile CEO Mike Sievert is hanging up his magenta hat, leaving the wireless giant’s board of directors and vice chair role effective Nov. Sievert will also leave the board’s Transaction Committee, according to a federal filing.