Michael Sievert is an American business executive, currently the president and chief executive officer (CEO) of T-Mobile US, and a member of the company's board of directors. In November 2019, |T-Mobile announced that Sievert would be promoted from chief operating officer (COO) to CEO in May 2020 when John Legere stepped down. Sievert took control a month earlier than planned, on April 1, 2020, the same day T-Mobile closed its merger with Sprint.