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).

1. Name and Address of Reporting Person* Vosseller Leigh (Last) (First) (Middle) C/O TANDEM DIABETES CARE, INC. 11075 ROSELLE STREET (Street) SAN DIEGO CA 92121 (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 and CFO
	3. Date of Earliest Transaction (Month/Day/Year) 05/16/2019
	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	05/16/2019		M		10,000(1)	A	$2.59	12,009	D
Common Stock	05/16/2019		S(2)		10,000	D	$70.45(3)	2,009	D
Common Stock	05/15/2019		A		1,256(4)	A	$16.93	3,265	D
Common Stock								145	I	Leigh A Vosseller Trust(5)

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
Stock Option	$2.59	05/16/2019		M			10,000	(6)	(7)	Common Stock	10,000	$0.00	60,000	D

Explanation of Responses:

1. Represents shares of common stock received upon exercise of a stock option award.

2. The shares were sold, pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person on March 7, 2019.

3. The price reported is the weighted average price. The shares were sold in multiple transactions at prices ranging from $70.35 to $70.60. 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.

4. The reporting person is voluntarily reporting the acquisition of shares of common stock pursuant to the Tandem Diabetes Care, Inc. 2013 Employee Stock Purchase Plan ("ESPP"), for the ESPP purchase period of November 16, 2018 through May 15, 2019. This transaction is also exempt under Rule 16b-3(c).

5. The securities are held by the Leigh A. Vosseller Trust dated January 17, 2010, of which Leigh Vosseller is the Trustee.

6. Fifty percent (50%) of the underlying shares subject to the option vested on 12/1/2018, and the remaining shares shall vest in twelve (12) equal monthly installments thereafter.

7. The expiration date for these options is 10 years from the date of grant.

Remarks:

	David B. Berger, Attorney-in-Fact for Leigh A. Vosseller	05/17/2019
	** 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).
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