Following her less than auspicious debut (her biggest line was "Daddy, I just saw a man carrying a naked lady"), she effectively stopped working to concentrate on her education, squeezing in only an occasional TV appearance (a 1986 Robert Zemeckis-directed segment of "Amazing Stories" and in the 1980 ABC movie "City of Fear"). By age 18, Masterson had decided to follow in her parents' stead and resumed her career, playing a cancer sufferer who beats the disease only to develop a drug habit and give birth to a drug-addicted baby in the soap opera-ish "Love Lives On" (ABC, 1985).
Masterson returned to features with the Catholic school comedy "Heaven Help Us" (1985), portraying the first of several roles in which she essayed tomboys. With her hair cropped short and her lean, gangly look, she excelled at the roles, although she came close to being typecast. A rare exception was her turn as Sean Penn's love interest in the dark, fact-based thriller, "At Close Range" (1986), Francis Ford Coppola also offered the performer a change of pace, casting her as the college sweetheart of a Vietnam-era soldier in 1987's "Gardens of Stone". (Coppola even hired Peter Masterson and his wife Carlin Glynn to play their real-life daughter's on screen parents.)
Moving to adult roles, Masterson earned plaudits for her turn as a pregnant woman who gives her baby to a wealthy couple in "Immediate Family" (1989) and found a signature part as the latent lesbian Idgie Threadgoode in the sleeper "Fried Green Tomatoes" (1991). She later appeared as the mentally disturbed painter Joon in the off-beat romance "Benny & Joon" (1993), co-starring Johnny Depp. But few of Masterson's films have been as successful as these ("really bad movies" and "bombs", she herself laughingly admitted), although she continued to prove to be a more than capable performer. She was one of a quartet of prostitutes roaming the untamed West in the revisionist "Bad Girls" (1994) and starred as a workaholic romanced by Christian Slater in the treacly romantic comedy "Bed of Roses" (1996).
Masterson was directed by her father in the well-received Showtime adaptation of Horton Foote's play "Lily Dale" in 1996. As the pampered, headstrong titular character who comes into conflict with her stepfather -- a role she had essayed on stage -- the actress delivered a strong turn that earned her critical kudos. The following year, she was seen as a single mother of a two in Timothy Hutton's feature directorial debut "Digging to China". Masterson herself has been anxious to step behind the camera, writing and directing the short "The Other Side" (lensed in 1999) and developing other projects as her anticipated big-screen debut. In the interim, with good roles for women hard to come by in motion pictures, she has turned to television, offering a fine performance as the abused wife of a police detective who tries to flee from her spouse in the thriller "Black and Blue" (CBS, 1999) and headlining her own series, "Kate Brasher" (CBS, 2001- ), portraying a single mother who finds a renewed sense of self as a caseworker for a legal advocacy center.