[1] He dropped out of college and moved to Los Angeles, California to pursue a career writing for sitcoms, starting with The Odd Couple.
In 1982, Ganz and Mandel teamed up with Happy Days actors Ron Howard and Henry Winkler to make their first film, the low-budget comedy Night Shift, which was also actor Michael Keaton's first film; Howard signed on because he wanted to start directing while Winkler wanted to move away from his image as the Fonz.
Ganz's second film outing, Splash, made stars of Tom Hanks and Daryl Hannah and earned him an Academy Award nomination for Best Original Screenplay.
Ganz and Mandel went on to write several other films, four more of which were also directed by Howard, and one of which had Penny Marshall, who starred in Laverne and Shirley, as director.
Ganz and Mandel are also widely used as Hollywood script doctors, known for their reliability and fast turnaround time.