X0508 4 2025-11-10 0 0001093557 DEXCOM INC DXCM 0001700255 Leach Jacob Steven 6340 SEQUENCE DRIVE SAN DIEGO CA 92121 0 1 0 0 President & COO 0 Common Stock 2025-11-10 4 P 0 15700 54.977 A 329197 D Common Stock 2025-11-10 4 P 0 2500 55.4252 A 331697 D Common Stock 47296 I Family Holdings This transaction was executed in multiple trades at prices ranging from $54.34 to $55.33. The price above reflects the weighted average purchase 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 $55.34 to $55.55. The price above reflects the weighted average purchase 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 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, and 8,465 of which were granted on March 8, 2023 and shall vest through March 8, 2026. 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. Exhibit 24 - Power of Attorney /s/ Jereme M. Sylvain, as Attorney-in-Fact for Jacob Steven Leach 2025-11-10