He is currently working on the NBC series Friday Night Lights as head writer and executive producer. Katims is also the creator of and executive producer for Parenthood, another NBC series which debuted in 2010. Katims was nominated for a Writers Guild of America Award for Best New Series at the February 2007 ceremony for his work on the first season of Friday Night Lights. He was nominated for the WGA Award for Best Dramatic Series the following year at the February 2008 ceremony for his work on the second season of Friday Night Lights. Katims was nominated for Best Dramatic Series a second time at the February 2009 ceremony for his work on the third season of Friday Night Lights. He was nominated for the WGA Award for Best Drama Series for the third consecutive year at the February 2010 ceremony for his work on the fourth season.

He also wrote a play titled The Man Who Couldn't Dance. Katims is a former member of Stagewrights, a playwriting collective in New York City.