[Form 4] Tandem Diabetes Care, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Tandem Diabetes Care insider Shannon M. Hansen reported multiple transactions on 08/15/2025 related to restricted stock units (RSUs) and common stock. The filing shows vesting-driven acquisitions: 531, 1,437 and 1,097 RSUs converted into common stock (total underlying 3,065 shares added to direct holdings) and corresponding increases in direct common stock ownership to a reported 7,677 shares of derivative-backed common stock and 19,102 shares of direct common stock at various steps. Several entries show shares withheld to satisfy tax withholding at $10.82 per share; no open-market sales were reported. The securities held indirectly are in the Shannon M. Hansen Trust.

Insights

Financial Analyst

TL;DR Routine officer RSU vesting and tax-withholding entries; no open-market sales, limited investor impact.

The Form 4 details customary vesting of RSUs awarded in 2022, 2023 and 2024 and the conversion or settlement mechanics. The transactions include share withholding to satisfy tax obligations at a reported price of $10.82 per share, which reduced the net shares delivered to the reporting person but did not involve market disposals. Reported direct beneficial ownership increases reflect standard compensation vesting rather than purchases or strategic reallocation. Overall, these are compensation-related movements with neutral material impact on capitalization or control.

Corporate Governance Expert

TL;DR Compensation vesting and trust holdings disclosed correctly; no governance red flags.

The filing identifies Shannon M. Hansen as EVP & Chief Legal Officer and trustee of the Shannon M. Hansen Trust. RSUs awarded under the 2013 and 2023 plans vested according to stated schedules, and the reporting clarifies that some shares were withheld solely for tax withholding rather than sold. The Form 4 properly discloses direct and indirect holdings and the trust relationship. There are no indications of unusual related-party transactions or departures from standard equity compensation practices.

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

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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^*

Hansen Shannon Marie

(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)
	EVP & Chief Legal Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/15/2025

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	08/15/2025		M		531	A	$0	17,273	D
Common Stock	08/15/2025		F		190(1)	D	$10.82	17,083	D
Common Stock	08/15/2025		M		1,437	A	$0	18,520	D
Common Stock	08/15/2025		F		515(1)	D	$10.82	18,005	D
Common Stock	08/15/2025		M		1,097	A	$0	19,102	D
Common Stock	08/15/2025		F		393(1)	D	$10.82	18,709	D
Common Stock								1,935	I	Shannon M. Hansen Trust(2)

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(3)	(4)	08/15/2025		M			531	(5)	(5)	Common Stock	531	$0	1,061	D
Restricted Stock Unit(6)	(7)	08/15/2025		M			1,437	(8)	(8)	Common Stock	1,437	$0	4,311	D
Restricted Stock Unit(9)	(7)	08/15/2025		M			1,097	(10)	(10)	Common Stock	1,097	$0	7,677	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. The securities are held by the Shannon M. Hansen Trust dated July 8, 2003, of which Shannon M. Hansen is the Trustee.

3. Awarded on February 15, 2022 pursuant to the Tandem Diabetes Care, Inc. 2013 Stock Incentive Plan, as amended, and the agreements related thereto (the 2013 Plan).

4. Each 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.

5. RSU vest as to twenty-five percent (25%) of the total number of shares subject to the RSU on 2/15/2023, and the remaining shares shall vest in twelve (12) equal quarterly installments thereafter.

6. Awarded on May 25, 2023 pursuant to the Tandem Diabetes Care, Inc. 2023 Long-Term Incentive Plan, as amended, and agreements related thereto (the 2023 Plan).

7. Each 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.

8. RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2024, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

9. Awarded on May 23, 2024 pursuant to the 2023 Plan.

10. RSU vest as to thirty-three percent (33%) of the total number of shares subject to the RSU on 5/15/2025, and the remaining shares shall vest in eight (8) equal quarterly installments thereafter.

Remarks:

	/s/ Rachel Malina, Attorney-in-Fact for Shannon M. Hansen	08/19/2025
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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