A Primetime Emmy Award winner, he is best known as a writer, executive producer, and supporting cast member on the NBC sitcom The Office, playing the role of Toby Flenderson.

[2] Lieberstein wrote references to the fact that Office character Andy Bernard was a Chi Psi from Cornell into the storyline of several episodes of the show.

[1] He then had short stints in a few other writer rooms, including Weird Science and The Naked Truth, before his brother-in-law Greg Daniels asked him to join the King of the Hill staff.

[1] On March 22, 2012, it was announced that Lieberstein would step down from his showrunner role to focus on a planned spin-off series featuring Rainn Wilson as Dwight Schrute, tentatively called The Farm.

Doing a scene with Steve Carell, trying to keep up with him, is as tough and fun and weird as any part of the process.Lieberstein's sister, Susanne, was the president of programming for YouTube Premium (previously holding this position at MTV), and is married to screenwriter and producer Greg Daniels.

[citation needed] Lieberstein married Janine Serafin Poreba on July 19, 2008, at the New York City restaurant Battery Gardens.

[3] He has served on the advisory board of directors for Young Storytellers, an arts education nonprofit organization based in Los Angeles.

In June 2007, he shared in a Daytime Emmy Award for "Outstanding Broadband Program – Comedy", for his work on The Office: Accountants webisodes.