X0306 4 2020-02-24 0 0001093557 DEXCOM INC DXCM 0001466545 DOUBLEDAY RICHARD 6340 SEQUENCE DRIVE SAN DIEGO CA 92121 0 1 0 0 EVP Chief Commercial Officer Common Stock 2020-02-24 4 S 0 467 275.9883 D 11779 I by Trust Common Stock 2020-02-24 4 S 0 852 278.031 D 10927 I by Trust Common Stock 2020-02-24 4 S 0 125 278.61 D 10802 I by Trust Common Stock 2020-02-24 4 S 0 88 283.0909 D 10714 I by Trust Common Stock 48444 D On June 3, 2019, Mr. Doubleday adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Doubleday. The shares set forth above were sold pursuant to the 10b5-1 Plan. This transaction was executed in multiple trades at prices ranging from $275.585 to $276.12. 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. Shares are held by the Doubleday Living Trust U/A/D 5/26/2015, with respect to which the reporting person is a trustee. This transaction was executed in multiple trades at prices ranging from $277.475 to $278.27. 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. This transaction was executed in multiple trades at prices ranging from $283.07 to $283.53. 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. By: Jereme Sylvain For: Richard B Doubleday 2020-02-26