Michael Seibel, a driving force behind Y Combinator’s accelerator program for more than a decade, is stepping back from his active role. He is officially transitioning to a Partner Emeritus position, a move that marks the end of his day-to-day involvement with YC but ensures his continued presence in an advisory capacity.
Seibel’s influence on YC spans over 12 years, during which he played a significant role in mentoring startups and diversifying the accelerator’s founder base. Although he had already scaled back his operational responsibilities at YC in recent months, this transition formally removes him from active leadership.
A Gradual Shift in Responsibilities
Seibel’s evolving role within YC has been years in the making. He initially joined as a part-time partner in 2013, later becoming the CEO of the YC Startup Accelerator in 2016. He led the accelerator through a period of substantial growth, refining its structure and expanding its reach.
His transition to Partner Emeritus comes after YC’s Winter 2025 batch wrapped up, finalizing a process he had already signaled in past announcements.
YC President and CEO Garry Tan acknowledged Seibel’s long-standing impact, noting how he shaped the accelerator’s evolution. “Michael has been an essential part of YC’s journey—from a founder to a group partner, managing director, and CEO of the accelerator. His influence will be felt for years to come.”
Shaping YC’s Diversity and Mentorship Model
Seibel was not just a mentor to startups—he also played a role in diversifying YC’s founder community. Under his leadership, YC actively sought to include more startups led by underrepresented founders. His work helped reshape the perception of what a YC-backed company could look like, opening doors for a broader range of entrepreneurs.
While YC has not yet named a direct replacement for Seibel’s role, the organization has emphasized that its core operations will continue without disruption.
Beyond YC: Seibel’s Mark on the Startup Ecosystem
Before joining YC, Seibel was already an accomplished entrepreneur. He co-founded Justin.tv in 2007, which later evolved into Twitch, now a dominant live-streaming platform. Amazon acquired Twitch for $970 million in 2014. He also co-founded Socialcam, a mobile video-sharing app acquired by Autodesk for $60 million in 2012.
Beyond his own startups, Seibel has served on the boards of Reddit and Dropbox, further cementing his influence in the tech industry. His investment portfolio includes companies like Cruise, Brex, and Figma, positioning him as a key figure in Silicon Valley’s startup scene.
While YC has defined much of Seibel’s career, he has suggested that his next chapter may take him beyond the startup world. Though he has not outlined specific plans, his interest in public service suggests a shift in focus.
What’s Next for YC?
Seibel’s departure from an active leadership role marks a shift, but YC remains steadfast in its mission. With Garry Tan at the helm, the accelerator continues to back and mentor early-stage startups while expanding its global footprint.
For now, YC has framed Seibel’s transition as a natural progression rather than a disruptive change. However, with one of its most influential leaders stepping back, the coming years may see new voices shaping the future of the world’s most famous startup accelerator.
