Blumberg was nominated for an Oscar for Best Original Screenplay in 2010 for co-writing The Kids Are All Right.

Blumberg made his directorial debut with the Hollywood film Thanks for Sharing starring Mark Ruffalo, Tim Robbins, Gwyneth Paltrow, Josh Gad, Joely Richardson, and Alecia Moore. The film is about sex addiction and how a group of New Yorkers deal with recovery.

Blumberg grew up in Shaker Heights, Ohio, and graduated from University School. He is of Jewish descent. He graduated from Yale University in 1991 with a BA in History, where Edward Norton was his roommate.