Rosen started his career in 1976, first writing a few episodes for the television series The Bob Newhart Show.[3] He also served in the army and graduated from college, in 1969.[4]
In 2007, Rosen wrote the book The Miracle Group.[6]
In 2018, Rosen screenplayed the short film The Matchmaker, which starred Barbara Bain, Rhea Perlman, Robert Romanus and Bryna Weiss. He explained that the short film was about an man who tries to find his mother a friend in her nursing home, which had also happened to Rosen.[7][8]