X0508 4 2026-01-29 0 0001093557 DEXCOM INC DXCM 0001700255 Leach Jacob Steven 6340 SEQUENCE DRIVE SAN DIEGO CA 92121 1 1 0 0 President, CEO, and Director 0 Common Stock 2026-01-29 4 A 0 8310 0 A 340109 D Common Stock 2026-01-29 4 F 0 3058 73.36 D 337051 D Common Stock 47296 I Family Holdings Represents shares issued to the Reporting Person upon vesting of performance-based restricted stock units (PSUs) granted to the Reporting Person on March 8, 2023, resulting from achievement of performance conditions under the PSUs. Represents the number of shares required to be withheld by the Issuer to cover tax withholding and remittance obligations in connection with the net settlement of PSUs and does not represent a sale by the Reporting Person. Included in this number are 84,537 unvested restricted stock units, 35,906 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 22,798 of which were granted on March 8, 2025 and shall vest through March 8, 2027, 17,368 of which were granted on March 8, 2024 and shall vest through March 8, 2027, 8,465 of which were granted on March 8, 2023 and shall vest through March 8, 2026, and 102 additional shares acquired under the Issuer's Amended and Restated 2015 Employee Stock Purchase Plan. Shares are held by the Gregg Family Grandchildren's Trust UAD 12/30/2010, with respect to which the Reporting Person's spouse is a trustee. /s/ Jereme M. Sylvain, as Attorney-in-Fact for Jacob Steven Leach 2026-02-02