Mac, 49, said once he gets his performance film "The Whole Truth, Nothing But The Truth, So Help Me Mac" in the theaters, "I'm going to call it," E News said.
He said he's been doing standup in clubs since 1977 and street performances for two years before that, and that was enough.
"I'm going to still do my producing, my films, but I want to enjoy my life a little bit," the Chicago native told David Letterman on the Monday night show. "I missed a lot of things, you know."
His movie credits include "Bad Santa" and "Ocean's Eleven," and a dramatic turn in the upcoming "Pride."
He also wrote two books, "I Ain't Scared Of You " and "Maybe You Never Cry Again."
Attkisson leaves CBS News, reportedly over network's 'liberal bias'
Duggar sisters unveil Christian dating rules in new book