Michael Seibel, a central figure in Y Combinator’s rise over the past decade, is stepping into a Partner Emeritus role after 12+ years at the accelerator. Seibel, who joined YC as a founder before rising to Managing Director and CEO of the accelerator program, announced the move via X (formerly Twitter), signaling a shift from operational duties to a more advisory capacity.
Seibel’s time at YC is marked by significant milestones. Initially going through YC’s program twice—once with Justin.TV (which later became Twitch) and again with Socialcam—he later played a key role as a Group Partner and then as the Managing Director of YC’s core accelerator. Seibel was instrumental in shaping YC’s program, mentoring thousands of startups, and helping to embed a strong founder-first culture at the organization.
While YC CEO Garry Tan celebrated Seibel’s contributions in an official blog post, noting the critical role he played in YC’s success, Seibel’s own message to the startup community hinted at what’s next. After a summer break, he plans to pursue work aimed at improving government services, calling it a return to a passion from his early career.
His move follows a gradual transition over recent years, beginning when Garry Tan took over as YC President and CEO in 2022—an appointment that reportedly surprised some YC insiders, many of whom viewed Seibel as the expected successor.
Despite stepping away from batch operations—marking the Winter 2025 batch as his last—Seibel will remain available to YC founders and alumni, hosting office hours and offering guidance to the many companies he has supported over the years.
Seibel’s next chapter reflects a growing trend of seasoned tech leaders pivoting toward public service or policy-driven projects. His departure comes just ahead of YC’s Spring 2025 batch, but the legacy he leaves behind will continue to shape YC’s approach to founder support and early-stage investing.
As Michael Seibel put it himself, YC and its leadership team “changed my life.” Now, as he looks to tackle inefficiencies in government systems, the startup world watches closely to see how one of Silicon Valley’s most influential mentors will make an impact beyond the tech ecosystem.
