X0306 4 2019-08-12 false 0001459839 SI-BONE, Inc. SIBN 0001296771 Freund John Gordon C/O SKYLINE VENTURES 525 UNIVERSITY AVENUE, SUITE 1350 PALO ALTO CA 94301 true false true false Common Stock 2019-08-12 4 S false 400000.00 18.25 D 4019985.00 I By Skyline Venture Partners V, L.P Shares held by Skyline Venture Partners V, L.P. ("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. Dr. Freund, a member of the Issuer's board of directors, together with Yasunori Kaneko, are the managing directors of LLC and each may be deemed to have voting and investment power with respect to the securities held by SVP V. Dr. Freund and Mr. Kaneko disclaim beneficial ownership of such securities, except to the extent of their pecuniary interest therein. /s/ Michael A. Pisetsky, Attorney-in-Fact for John G. Freund 2019-08-14