In the 1980s, she co-starred with her twin sister Jean Sagal in the 23-episode television series Double Trouble that ran from 1984–85, as well as the 1982 movie Grease 2, a loose sequel to the 1978 film starring John Travolta. She has since appeared on such shows as Knots Landing and Picket Fences.
She played a part in the film Howard the Duck, as a member of the fictional band "Cherry Bomb", in conjunction with which she contributed vocals to the songs "Hunger City", "Don't Turn Away (Reprise)", "It Don't Come Cheap" and "Howard the Duck".
Sagal is part of a family of entertainment industry professionals. She is the daughter of director Boris Sagal and the stepdaughter of Marge Champion. Her siblings, older sister Katey Sagal, brother Joe Sagal and twin sister, Jean Sagal, are all notable in the industry. She also has a brother David Sagal who is an attorney.