Lembeck was born in Brooklyn, New York, the son of Caroline Dubs and Harvey Lembeck, an actor and Comedian. He began acting in the late 1960s and directing in the 1970s. His most notable acting role was as Julie Cooper's husband, Max Horvath, on the sitcom One Day at a Time. He played newscaster Clete Meizenheimer on the series Mary Hartman, Mary Hartman. In 1975, he appeared on Barney Miller in the episode "Hair" as Officer Guardeno. He also played "Kaptain Kool" of Kaptain Kool and the Kongs on The Krofft Supershow from 1976 to 1978. He is also known for his role as Vinnie Fazio in The Boys in Company C in 1978. He was a member of the cast of the 1985–1986 situation comedy Foley Square. He also appeared with his father, actor Harvey Lembeck, in an episode of The Partridge Family in 1971.
Lembeck's first film appearance came in the 1968 film Hang 'Em High where he portrays a store clerk with two spoken lines. He later acted in The In-Laws. He directed The Santa Clause 2 and The Santa Clause 3: The Escape Clause, as well as the Nia Vardalos film Connie and Carla and Tooth Fairy.
