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 * Freund John Gordon	2. Issuer Name and Ticker or Trading Symbol SI-BONE, Inc. [ SIBN ]	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 SKYLINE VENTURES, 525 UNIVERSITY AVENUE, SUITE 1350	3. Date of Earliest Transaction (MM/DD/YYYY) 6/14/2021
(Street) PALO ALTO, CA 94301 (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	6/14/2021		S		17990.00	D	$31.2806 (1)	365468.00	I	By Skyline Venture Partners V, LP
Common Stock	6/15/2021		S		21511.00	D	$31.1067 (2)	343957.00	I	By Skyline Venture Partners V, LP
Common Stock	6/16/2021		S		12591.00	D	$31.4055 (3)	331366.00	I	By Skyline Venture Partners V, LP (4)
Common Stock								12645.00 (5)	D
Common Stock								100750.00	I	By John Freund Family Partnership IV, L.P (6)

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)	The price reported in column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $31.09 to $31.65, inclusive. The Reporting Person undertakes to provide the Issuer, any securityholder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in these footnotes.
(2)	The price reported in column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $30.74 to $31.75, inclusive. The Reporting Person undertakes to provide the Issuer, any securityholder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in these footnotes.
(3)	The price reported in column 4 is a weighted-average price. The shares were sold in multiple transactions ranging from $30.84 to $31.96, inclusive. The Reporting Person undertakes to provide the Issuer, any securityholder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in these footnotes.
(4)	Shares held by SVP V. Skyline Venture Management V, LLC ("LLC") is the general partner of SVP V and as such may be deemed to have voting and investment power with respect to the securities of SVP V. Reporting Person, a member of Issuer's board of directors, is a managing director of LLC and may be deemed to have voting and investment power with respect to the securities held by SVP V. Reporting Person disclaims beneficial ownership of such securities, except to the extent of his pecuniary interest therein.
(5)	Includes 3,848 shares issuable on the settlement of restricted stock units granted to the Reporting Person. Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock.
(6)	Shares held by John Freund Family Partnership IV, L.P. ("Family LP"). Reporting Person, a member of Issuer's board of directors, is a general partner of Family LP and may be deemed to have voting and investment power with respect to the securities held by Family LP. Reporting Person disclaims beneficial ownership of such securities, except to the extent of his pecuniary interest therein.

Reporting Owners
Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
Freund John Gordon C/O SKYLINE VENTURES 525 UNIVERSITY AVENUE, SUITE 1350 PALO ALTO, CA 94301	X

Signatures
/s/ Michael A. Pisetsky, Attorney-in-Fact for John G. Freund		6/16/2021
**Signature of Reporting Person		Date