X0306 4 2016-10-10 0 0001093557 DEXCOM INC DXCM 0001236388 GREGG TERRANCE H 6340 SEQUENCE DRIVE SAN DIEGO CA 92121 1 1 0 0 Executive Chairman Common Stock 2016-10-10 4 D 0 2167.0 83.35 D 447116 D Common Stock 11461 I by IRA Common Stock 65882 I by Trust These shares were sold to cover the Company's tax withholding obligation that accrued in connection with the vesting of restricted stock units previously granted. Included in this number are 59,391 unvested restricted stock units, 34,000 of which were granted on March 8, 2016 and will vest on March 8, 2017 and 25,391 unvested restricted stock units granted on March 8, 2014, 5,078 of which shall vest each month through March 8, 2017. Shares are held by the Gregg Family Trust U/A/D 12/23/1998, with respect to which the reporting person is a trustee. By: Timothy O'Brien For: Terrance H. Gregg 2016-10-11