X0306 4 2018-05-07 0 0001283699 T-Mobile US, Inc. TMUS 0001182438 SIEVERT G MICHAEL C/O T-MOBILE US, INC. 12920 SE 38TH STREET BELLEVUE WA 98006 1 1 0 0 Chief Operating Officer Common Stock 2018-05-07 4 S 0 2556 56.5029 D 467225 D Common Stock 2018-05-07 4 S 0 500 57.366 D 466725 D Common Stock 2018-05-08 4 S 0 3096 56.0853 D 463629 D The sale was effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on November 14, 2017. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $56.05 to $57.005. The reporting person undertakes to provide T-Mobile US, Inc. (the "Company"), any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $57.11 to $57.63. The reporting person undertakes to provide the Company any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $55.70 to $56.70. The reporting person undertakes to provide the Company any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote. /s/ David A. Miller, Attorney-in-Fact 2018-05-09