On June 12, 2008, "Variety" magazine reported that Lieberstein would become one of the executive producers of "The Office". He worked in the writer's room from the start of the US adaptation and was asked by Greg Daniels to act as well, as Greg wanted some of the writers to know what it was like on the other side of the camera. Lieberstein has said he "attended 'The Office' acting school" and was often thrown by Steve Carell's improv during scenes.