Statement of Changes in Beneficial Ownership (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).

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

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

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3235-0287

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Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person * BLICKENSTAFF KIM D	2. Issuer Name and Ticker or Trading Symbol TANDEM DIABETES CARE INC [ TNDM ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director                    _____ 10% Owner _____ Officer (give title below)    _____ Other (specify below)
(Last)          (First)          (Middle) C/O TANDEM DIABETES CARE, INC., 11075 ROSELLE STREET	3. Date of Earliest Transaction (MM/DD/YYYY) 8/10/2021
(Street) SAN DIEGO, CA 92121 (City)        (State)        (Zip)	4. If Amendment, Date Original Filed (MM/DD/YYYY)	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. Trans. Date	2A. Deemed Execution Date, if any	3. Trans. 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	8/10/2021		S		3210 (1)	D	$107.2069 (2)	316380	I	See Footnote (3)
Common Stock								1892	D

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivate Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Trans. Date	3A. Deemed Execution Date, if any	4. Trans. 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		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 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

Explanation of Responses:
(1)	Shares sold are from long shares held by the Kim Blickenstaff Revocable Trust, dated April 15, 2010.
(2)	The price reported reflects the weighted average price per share of multiple transactions with prices per share ranging between $107.00 to $107.76. The Reporting Person undertakes to provide the Securities and Exchange Commission (the "SEC"), the issuer, and any security holder full information regarding the number of shares and the prices at which the shares were sold.
(3)	The securities are held by the Kim Blickenstaff Revocable Trust dated April 15, 2010.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
BLICKENSTAFF KIM D C/O TANDEM DIABETES CARE, INC. 11075 ROSELLE STREET SAN DIEGO, CA 92121	X

Signatures
s/ David B. Berger, Attorney-in-Fact for Kim D. Blickenstaff		8/12/2021
**Signature of Reporting Person		Date