Statement of Changes in Beneficial Ownership (Form 4)

FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b). Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response... 0.5

(Print or Type Responses)

1. Name and Address of Reporting Person * Leach Jacob Steven 2. Issuer Name and Ticker or Trading Symbol DEXCOM INC [DXCM] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) President, CEO, and Director (Last) (First) (Middle) 6340 SEQUENCE DRIVE 3. Date of Earliest Transaction (Month/Day/Year) 03/08/2026 (Street) SAN DIEGO, CA 92121 4. If Amendment, Date Original Filed (Month/Day/Year) 6. Individual or Joint/Group Filing (Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock 03/08/2026 A 104,516(1) A $ 0 441,567 D Common Stock 03/08/2026 F 19,757(2) D $68.1 421,810(3) D Common Stock 47,296 I Family Holdings(4)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
	Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.		SEC 1474 (9-02)

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Leach Jacob Steven 6340 SEQUENCE DRIVE SAN DIEGO, CA 92121	X		President, CEO, and Director

Signatures

/s/ Jereme M. Sylvain, as Attorney-in-Fact for Jacob Steven Leach		03/10/2026
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	Represents a grant of restricted stock units (RSUs) that are exempt from Section 16b-3 and are subject to vesting in three equal annual installments from the date of grant. RSUs represent a contingent right to receive one share of DexCom, Inc. Common Stock.
(2)	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 RSUs and does not represent a sale by the Reporting Person.
(3)	Included in this number are 148,536 unvested RSUs, 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, 11,399 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.
(4)	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.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure. Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.