shimerman was born to a jewish family in lakewood, new jersey, the son of susan, an accountant, and herbert shimerman, a house painter. when shimerman was 15, his family moved to los angeles, where his mother enrolled him in a drama group in an effort to expand his social circle. shimerman attended santa monica high school and was active in drama. as a senior, he played leading roles in school productions of "hamlet", "the crucible" and "the skin of our teeth" before graduating in 1967. after graduating from ucla, shimerman was selected to apprentice at the old globe theater in san diego. shimerman began pursuing a dramatic career in theater, eventually moving to new york, where he was a member of the impossible ragtime theater. returning to los angeles, shimerman received roles in two cbs series, launching his television acting career.