Tandem Diabetes Care (TNDM) CTO details 406 RSU vesting, 207 shares withheld

Rhea-AI Filing Summary

Tandem Diabetes Care Inc. reported an insider equity transaction by its Chief Technology Officer, Rick A. Carpenter. On 12/15/2025, 406 restricted stock units (RSUs) granted on 12/15/2021 under the company’s 2013 Stock Incentive Plan were converted into common stock at an exercise price of $0.

To cover tax withholding on the RSU vesting, the company withheld 207 shares at a price of $22.11 per share, and no shares were sold on the open market. After these transactions, Carpenter directly holds 24,252 shares of Tandem Diabetes Care common stock.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

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

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 for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Carpenter Rick

(Last) (First) (Middle)

12400 HIGH BLUFF DRIVE

(Street)

SAN DIEGO CA 92130

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
TANDEM DIABETES CARE INC [ TNDM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Technology Officer

3. Date of Earliest Transaction (Month/Day/Year)
12/15/2025

4. If Amendment, Date of 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

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	12/15/2025		M		406	A	$0	24,459	D
Common Stock	12/15/2025		F(1)		207	D	$22.11	24,252	D

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 Securities Underlying Derivative Security (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: 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
Restricted Stock Unit(2)	(3)	12/15/2025		M			406	(4)	(4)	Common Stock	406	$0	0	D

Explanation of Responses:

1. Shares withheld by Tandem Diabetes Care Inc. (the Company) to satisfy tax withholding requirements on vesting of restricted stock units (RSU). No shares were sold.

2. Awarded on December 15, 2021 pursuant to the Tandem Diabetes Care Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan).

3. RSU represents a contingent right to receive either one share of common stock of the Issuer or cash in lieu thereof, at the Issuer's discretion, in accordance with the terms of the 2013 Plan.

4. RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 12/15/2022, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.

Remarks:

	/s/ Shannon M. Hansen, Attorney-in-Fact for Rick A. Carpenter	12/17/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* 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).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
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 Number.

FAQ

What insider transaction did Tandem Diabetes Care (TNDM) report in this Form 4?

The Chief Technology Officer, Rick A. Carpenter, reported the vesting and settlement of 406 restricted stock units (RSUs) into common stock on 12/15/2025.

How many Tandem Diabetes Care (TNDM) shares were withheld for taxes?

Tandem Diabetes Care withheld 207 shares of common stock at $22.11 per share to satisfy tax withholding obligations related to the RSU vesting.

Did the Tandem Diabetes Care (TNDM) insider sell any shares in the market?

No. The filing states that the shares were withheld by Tandem Diabetes Care Inc. to satisfy tax withholding requirements and that no shares were sold.

How many Tandem Diabetes Care (TNDM) shares does the CTO own after this transaction?

Following the reported transactions, Rick A. Carpenter beneficially owns 24,252 shares of Tandem Diabetes Care common stock directly.

When were the reported RSUs originally granted to the Tandem Diabetes Care (TNDM) CTO?

The RSUs were awarded on 12/15/2021 under the Tandem Diabetes Care Inc. 2013 Stock Incentive Plan.

What is the vesting schedule for the reported Tandem Diabetes Care (TNDM) RSUs?

The RSUs vest as to 25% of the total shares on 12/15/2022, with the remaining shares vesting in 12 equal quarterly installments thereafter.