X0306 4 2014-10-08 0 0001093557 DEXCOM INC DXCM 0001343856 VALDES JORGE A 6340 SEQUENCE DRIVE SAN DIEGO CA 92121 0 1 0 0 CTO Common Stock 2014-10-08 4 M 0 16000.0 7.25 A 134748 D Common Stock 2014-10-08 4 S 0 16000.0 40.2907 D 118748 D Common Stock 75535 I by Trust Non-Qualified Stock Option (right to buy) 7.25 2014-10-08 4 M 0 16000.0 40.2907 D 2008-03-09 2017-03-09 Common Stock 16000 35562 D On November 15, 2013, Mr. Valdes adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Valdes. The shares set forth above were sold pursuant to the 10b5-1 Plan. This transaction was executed in multiple trades at prices ranging from $40.00 to $40.62. The price above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transactions were effected. Included in this number are 118,748 unvested restricted stock units, 71,000 of which were granted on March 8, 2014 and shall vest through March 8, 2017, 35,811 of which were granted on March 11, 2013 and shall vest through March 11, 2016, and 11,937 of which were granted on March 8, 2012 and shall vest through March 8, 2015. Shares are held by the Valdes-Lopez-Calleja Family Trust U/A/D 05/18/2011, with respect to which the reporting person is a trustee. By: Jess Roper For: Jorge Valdes 2014-10-09