DEXCOM INC (DXCM) Insider Transactions

Reported filing row; may be amended. Do not sum filings blindly.

F1 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 restricted stock units and does not represent a sale by the Reporting Person.

F2 Included in this number are 84,244 unvested restricted stock units, 48,774 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 23,937 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 2,849 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 8,684 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 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 restricted stock units and does not represent a sale by the Reporting Person.

F2 Included in this number are 69,053 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 2,849 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 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 restricted stock units and does not represent a sale by the Reporting Person.

F2 Included in this number are 139,986 unvested restricted stock units, 104,516 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 23,937 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 2,849 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 8,684 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

F3 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.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 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 restricted stock units and does not represent a sale by the Reporting Person.

F2 Included in this number are 69,053 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 2,849 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 Represents unvested restricted stock units, 5,565 of which were granted on May 28, 2026 and will vest on the earlier of the one year anniversary of the grant date or the date of DexCom, Inc.'s 2027 Annual Meeting of Stockholders, and 4,777 of which were granted on October 24, 2025 and shall vest through October 24, 2028.

F2 On October 30, 2026, the Reporting Person transferred 2,389 shares of the Issuer's common stock to the Ashley Family Revocable Living Trust for no consideration.

F3 Shares are held by the Ashley Family Revocable Living Trust, with respect to which the Reporting Person and the Reporting Person's spouse are co-trustees.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On May 28, 2026, Ms. Stern adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Ms. Stern. The shares set forth above were sold pursuant to the 10b5-1 Plan.

F2 Included in this number are 71,903 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On November 26, 2025, Mr. Brown adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Brown. The shares set forth above were sold pursuant to the 10b5- 1 Plan.

F2 Included in this number are 71,903 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On May 28, 2026, Ms. Stern adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Ms. Stern. The shares set forth above were sold pursuant to the 10b5-1 Plan.

F2 Included in this number are 71,903 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On June 10, 2026, Mr. Augustinos adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Augustinos. The shares set forth above were sold pursuant to the 10b5-1 Plan.

F2 Shares are held by the Kirschner/Augustinos Revocable Trust, with respect to which the Reporting Person is a trustee.

F3 Represents unvested restricted stock units which were granted on May 28, 2026 and will vest on the earlier of the one year anniversary of the grant date or the date of DexCom, Inc.'s 2027 Annual Meeting of Stockholders.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On November 26, 2025, Mr. Brown adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Brown. The shares set forth above were sold pursuant to the 10b5- 1 Plan.

F2 Included in this number are 71,903 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027, and 83 additional shares acquired under the Issuer's Amended and Restated 2015 Employee Stock Purchase Plan.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On June 10, 2026, Mr. Augustinos adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Augustinos. The shares set forth above were sold pursuant to the 10b5-1 Plan.

F2 Shares are held by the Kirschner/Augustinos Revocable Trust, with respect to which the Reporting Person is a trustee.

F3 Represents unvested restricted stock units which were granted on May 28, 2026 and will vest on the earlier of the one year anniversary of the grant date or the date of DexCom, Inc.'s 2027 Annual Meeting of Stockholders.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On June 10, 2026, Mr. Sylvain adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Sylvain. The shares set forth above were sold pursuant to the 10b5-1 Plan.

F2 Included in this number are 87,094 unvested restricted stock units, 48,774 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 23,937 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, 8,684 of which were granted on March 8, 2024 and shall vest through March 8, 2027, and 76 additional shares acquired under the Issuer's Amended and Restated 2015 Employee Stock Purchase Plan.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 Represents a grant of restricted stock units that are exempt from Section 16b-3 and are subject to vesting in three equal annual installments from the date of grant. Restricted stock units represent a contingent right to receive one share of DexCom, Inc. Common Stock.

F2 Shares are held by the Boehnlein 2017 Trust, with respect to which the Reporting Person and the Reporting Person's spouse are co-trustees.

References: F1

Reported filing row; may be amended. Do not sum filings blindly.

F1 On May 28, 2026, Ms. Stern adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Ms. Stern. The shares set forth above were sold pursuant to the 10b5-1 Plan.

F2 Included in this number are 71,903 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 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 restricted stock units and does not represent a sale by the Reporting Person.

F2 Included in this number are 142,836 unvested restricted stock units, 104,516 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 23,937 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 8,684 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

F3 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.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 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 restricted stock units and does not represent a sale by the Reporting Person.

F2 Included in this number are 87,094 unvested restricted stock units, 48,774 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 23,937 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 8,684 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 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 restricted stock units and does not represent a sale by the Reporting Person.

F2 Included in this number are 71,903 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 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 restricted stock units and does not represent a sale by the Reporting Person.

F2 Included in this number are 71,903 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 5,699 of which were granted on March 8, 2025 and shall vest through March 8, 2027, and 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On February 18, 2026, Mr. Sayer adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Sayer. The shares set forth above were sold pursuant to the 10b5- 1 Plan.

F2 This transaction was executed in multiple trades at prices ranging from $89.275 to $90.25. 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.

F3 Included in this number are 106,972 unvested restricted stock units, 32,749 of which were granted on March 8, 2026 and shall vest through March 8, 2027, 56,993 of which were granted on March 8, 2025 and shall vest through March 8, 2028, and 17,230 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

F4 This transaction was executed in multiple trades at prices ranging from $90.32 to $91.19. 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.

References: F1, F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 On February 18, 2026, Mr. Sayer adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Sayer. The shares set forth above were sold pursuant to the 10b5- 1 Plan.

F2 This transaction was executed in multiple trades at prices ranging from $89.275 to $90.25. 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.

F3 Included in this number are 106,972 unvested restricted stock units, 32,749 of which were granted on March 8, 2026 and shall vest through March 8, 2027, 56,993 of which were granted on March 8, 2025 and shall vest through March 8, 2028, and 17,230 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

F4 This transaction was executed in multiple trades at prices ranging from $90.32 to $91.19. 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.

References: F1, F4, F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 On February 18, 2026, Mr. Sayer adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Sayer. The shares set forth above were sold pursuant to the 10b5- 1 Plan.

F2 This transaction was executed in multiple trades at prices ranging from $89.275 to $90.25. 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.

F3 Included in this number are 106,972 unvested restricted stock units, 32,749 of which were granted on March 8, 2026 and shall vest through March 8, 2027, 56,993 of which were granted on March 8, 2025 and shall vest through March 8, 2028, and 17,230 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

F4 This transaction was executed in multiple trades at prices ranging from $90.32 to $91.19. 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.

References: F1, F2, F3

Reported filing row; may be amended. Do not sum filings blindly.

F1 On November 26, 2025, Mr. Brown adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Brown. The shares set forth above were sold pursuant to the 10b5- 1 Plan.

F2 Included in this number are 74,753 unvested restricted stock units, 39,019 of which were granted on March 8, 2026 and shall vest through March 8, 2029, 19,948 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 8,549 of which were granted on March 8, 2025 and shall vest through March 8, 2027, 7,237 of which were granted on March 8, 2024 and shall vest through March 8, 2027.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On August 14, 2025, Ms. Heller adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Ms. Heller. The shares set forth above were sold pursuant to the 10b5-1 Plan.

F2 Included in this number are 5,575 unvested restricted stock units which were granted on May 28, 2026 and will vest on the earlier of the one year anniversary of the grant date or the date of DexCom, Inc.'s 2027 Annual Meeting of Stockholders.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 Represents a donation of shares to a charitable donor advised fund.

F2 Shares are held by the Kirschner/Augustinos Revocable Trust, with respect to which the Reporting Person is a trustee.

F3 Represents unvested restricted stock units which were granted on May 28, 2026 and will vest on the earlier of the one year anniversary of the grant date or the date of DexCom, Inc.'s 2027 Annual Meeting of Stockholders.

References: F1, F2

Reported filing row; may be amended. Do not sum filings blindly.

F1 On March 13, 2026, The Foletta Family Trust DTD 1/30/2015 (the "Trust") adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by the Trust. The shares set forth above were sold pursuant to the 10b5-1 Plan.

F2 Shares are held by The Foletta Family Trust DTD 1/30/2015, with respect to which the Reporting Person is a trustee.

F3 Represents unvested restricted stock units which were granted on May 28, 2026 and will vest on the earlier of the one year anniversary of the grant date or the date of DexCom, Inc.'s 2027 Annual Meeting of Stockholders.

References: F1, F2