Michael Seibel announced late Wednesday on X that after more than 12 years at the famed accelerator Y Combinator, he is transitioning to a partner emeritus role.Y Combinator CEO Garry Tan shared the news separately in a company blog post, highlighting Seibels long history with the outfit. Seibel first joined YC as a founder, going through the program twice once with the streaming startup Justin.TV and later with the streaming app Socialcam. Seibel later served as a group partner, managing director, and CEO of the YC accelerator.Notably, Seibel had already stepped back into a less operational group partner role recently. In a YC blog post last year, he wrote that he was ready to hand over my leadership responsibilities, with the transition becoming effective after the accelerators winter batch of startups completed the program.A dozen years is a long tenure for anyone, but Seibels departure may have been set in motion as early as 2022, when Tan was appointed President and CEO. The move reportedly surprised some YC employees partly because Tan was running a separate venture fund at the time outside of YC, but also because they believed Seibel to be next in line for the role.Weve reached out to Seibel for comment. In the meantime, he shared in his X post that after taking this coming summer to relax, hes eager to help government better serve its citizens. He added, Government was the passion of my youth, and Im excited to reengage. Seibel signed off by thanking Y Combinator founders Paul Graham and Jessica Livingston for changing my life.The news comes roughly two weeks before YCs spring batch of founders kick off their own tour of duty; the program will run from April through June.Topics