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	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response... 0.5
	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 * ROEDER DOUGLAS A	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 DELPHI VENTURES,, 63 BOVET ROAD, SUITE 351	3. Date of Earliest Transaction (MM/DD/YYYY) 6/13/2019
(Street) SAN MATEO, CA 94402 (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	6/13/2019		S (1)		35343	D	$70.0697   (2)	1318243	I	See footnote   (3)
Common Stock	6/13/2019		S (1)		345	D	$70.0697   (2)	12872	I	See footnote   (4)

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)	This transaction was effected pursuant to a Rule 10b5-1 trading plan entered into on May 14, 2019.
(2)	This transaction was executed in multiple trades at prices ranging from $70.00 to $70.35. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issuer full information regarding the number of shares and prices at which the transaction was effected.
(3)	The Reporting Person is a managing member of Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of Delphi Ventures VIII, L.P. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by Delphi Ventures VIII, L.P. and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities held by Delphi Ventures VIII, L.P., except to the extent of his proportionate pecuniary interest therein.
(4)	The Reporting Person is a managing member of Delphi Management Partners VIII, L.L.C. ("DMP"), the general partner of Delphi BioInvestments VIII, L.P. As a managing member of DMP, the Reporting Person shares voting and investment power over the securities held by Delphi BioInvestments VIII, L.P. and may be deemed to have indirect beneficial ownership of such shares. The Reporting Person disclaims beneficial ownership of such securities held by Delphi BioInvestments VIII, L.P., except to the extent of his proportionate pecuniary interest therein.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ROEDER DOUGLAS A C/O DELPHI VENTURES, 63 BOVET ROAD, SUITE 351 SAN MATEO, CA 94402	X

Signatures
/s/ Matthew T. Potter, by power of attorney for Douglas A. Roeder		6/17/2019
** 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).
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 control number.