Y Combinator Adds Four Part-Time Partners, Including Groupon’s Andrew Mason (Who’s Also Starting A New Company)

Y Combinator’s Paul Graham revealed a bunch of personnel news in a just-published blog post.

Let’s see if I’ve got everything: The incubator has added one full-time partner (Wufoo’s Kevin Hale) and four part-time partners (Socialcam’s Michel Seibel, Hipmunk’s Steve Huffman, imeem and App.net’s Dalton Caldwell and Groupon’s Andrew Mason). Current partner Harj Taggar, meanwhile, is leaving “to start a new startup (in the long term) and travel the world (in the short),” but Graham writes that Taggar will stay on as a part-time partner.

YC first began bringing on part-time partners two years ago — it now has 10 partners, plus eight part-time partners. As with the other, previously announced part-timers, these additions are mostly YC alums — the exceptions are Caldwell (who I’ve seen speak at numerous YC events) and Mason, who was recently fired from the CEO job at Groupon.

The obvious significance here is that YC has basically doubled the team of part-time partners. Graham also notes that with the addition of Hale, two of the incubator’s partners are designers, “which partly reflects the increasing importance of design in startups, but frankly mostly reflects the fact that they’re really good.”

Update: Mason also has his own blog post announcing that he’s joining YC, but also stating that he’s starting a new company, moving to San Francisco, and releasing an album of “motivational business music.” On the company front, he doesn’t say much:

I feel very lucky to be alive at a time when someone like me can have a simple idea like Groupon that ends up impacting millions of people. If there’s a silver lining to leaving Groupon, it’s the opportunity to start something new. I’ve accumulated a backlog of ideas over the last several years, my favorite of which I’ll be turning into a new company this fall.