X0609 4 2026-10-05 0 0001699350 SHOULDER INNOVATIONS, INC. SI 0001474322 Tansey Casey M false C/O SHOULDER INNOVATIONS, INC. 1535 STEELE AVENUE SW, SUITE B GRAND RAPIDS MI 49507 1 0 1 0 0 Common Stock 2026-10-05 4 A 0 733 19.60 A 53445 D Common Stock 1686403 I Held by U.S. Venture Partners XII, L.P. Common Stock 85586 I Held by U.S. Venture Partners XII-A, L.P. Common Stock 921130 I Held by U.S. Venture Partners Select Fund I, L.P. Represents an award of restricted stock units ("RSUs") received in lieu of cash retainer fees, which were fully vested as of the grant date. Each RSU represents a contingent right to receive one share of the Issuer's Common Stock and has no expiration date. The Reporting Person voluntarily elected to defer receipt of the Common Stock issuable upon settlement of the RSUs until the Reporting Person's departure from the Board of Directors. Presidio Management Group XII, L.L.C. ("PMG XII") is the general partner of U.S. Venture Partners XII, L.P. ("USVP XII") and U.S. Venture Partners XII-A, L.P. ("USVP XII-A") and has sole voting and dispositive power with respect to the shares held by USVP XII and USVP XII-A. Steven M. Krausz, Richard W. Lewis, Jonathan D. Root and Dafina Toncheva are the managing members of PMG XII, and share voting and dispositive power with respect to the shares held by USVP XII and USVP XII-A. Casey M. Tansey is the managing partner of PMG XII and may be deemed to share voting and dispositive power over the reported securities held by USVP XII and USVP XII-A. Presidio Management Group Select Fund I, L.L.C. ("PMG Select") is the general partner of U.S. Venture Partners Select Fund I, L.P. ("USVP SFI"), and U.S. Venture Partners Select Fund I-A, L.P. ("USVP SFI-A") and has sole voting and dispositive power with respect to the shares held by USVP SFI on its own behalf and as nominee for USVP SFI-A. Richard W. Lewis, Jonathan D. Root and Dafina Toncheva are the managing members of PMG Select and share voting and dispositive power with respect to the shares held by USVP SFI on its own behalf and as nominee for USVP SFI-A. Casey M. Tansey, a member of the Issuer's board of directors, is the managing partner of PMG Select and may be deemed to share voting and dispositive power with respect to the shares held by USVP SFI on its own behalf and as nominee for USVP SFI-A. Each of the managing members and managing partner of PMG XII and PMG Select disclaims beneficial ownership of such holdings, except to the extent of their pecuniary interest in the shares. /s/ Jeffrey Points, as Attorney-in-Fact 2026-10-06