Leigh A. Vosseller - 30 May 2025 Form 4 Insider Report for TANDEM DIABETES CARE INC (TNDM)

Role: EVP & CHIEF FINANCIAL OFFICER
Signature: /s/ Rachel Malina, Attorney-in-Fact for Leigh A. Vosseller
Issuer symbol: TNDM
Transactions as of: 30 May 2025
Net transactions value: $0
Form type: 4
Filing time: 05 Jun 2025, 17:30:32 UTC
Previous filing: 19 May 2025
Next filing: 11 Aug 2025
SEC: View on sec.gov

Reporting Owners (1)

Name	Relationship	Address	Signature	Signature date	CIK
Vosseller Leigh	EVP & CHIEF FINANCIAL OFFICER	12400 HIGH BLUFF DRIVE, SAN DIEGO	/s/ Rachel Malina, Attorney-in-Fact for Leigh A. Vosseller	05 Jun 2025	0001726322

Transactions Table

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Ownership	Footnotes
holding	TNDM	Common Stock						33,798	30 May 2025	Direct
holding	TNDM	Common Stock						11,860	30 May 2025	Leigh A. Vosseller Trust	F1

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
transaction	TNDM	Performance Stock Unit	Award	$0	+31,486		$0.000000	31,486	30 May 2025	Common Stock	31,486		Direct	F2, F3
transaction	TNDM	Restricted Stock Unit	Award	$0	+31,488		$0.000000	31,488	30 May 2025	Common Stock	31,488		Direct	F2, F4, F5

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	The securities are held by the Leigh A. Vosseller Trust dated January 17, 2010, of which Leigh Vosseller is the Trustee.
F2	Awarded on May 30, 2025 pursuant to the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan, as amended, and agreements related thereto (the 2023 Plan).
F3	Each performance stock unit (PSU) represents a contingent right to receive one share of Tandem Diabetes Care, Inc. (the Company) common stock based upon the achievement of certain pre-defined performance metrics as of December 31, 2027 (the Measurement Date). The number of shares issued may range from 0% to 200% of the amount specified above, based upon (i) Company's actual performance relative to the pre-defined performance metrics, and (ii) subject to the awardee's continuing service through the Measurement Date. If minimum performance metrics are not met, no PSUs will vest.
F4	Each restricted stock unit (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 2023 Plan.
F5	RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2026, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.