Born and raised in Manhattan, a graduate of Brown University, Michael comes from a long line of filmmakers. His grandfather, Oscar-winning screenwriter Sidney Buchman, ran Columbia Pictures under Harry Cohn throughout the 1930s and 1940s and wrote and produced such films as Mr. Smith Goes to Washington (1939), Here Comes Mr. Jordan (1941), The Talk of the Town (1942), The Awful Truth (1937) Sahara (1943), A Song to Remember (1945), Holiday (1938), Lost Horizon (1937), The Jolson Story (1946), Cleopatra (1934), Theodora Goes Wild (1936) and more than 20 others. He was blacklisted in 1951 but continued to write from Cannes until his death in 1975.

Michael's sister, Amanda Silver, wrote The Hand That Rocks the Cradle (1992) and she and her husband, Rick Jaffa, wrote and produced Rise of the Planet of the Apes and Dawn of the Planet of the Apes, among others. They are currently writing Avatar 2, due 2016.