Masterson co-wrote (with Larry L. King) the books for the hit musical The Best Little Whorehouse in Texas (1978) and its short-lived sequel The Best Little Whorehouse Goes Public (1994). In 1980, he produced the ABC television movie,"City in Fear" based on an idea by screenwriter William Goldman—an idea that became the well-reviewed 1979 novel"Panic on Page One" by Linda Stewart, and the television script by Albert Ruben. The cast was led by Robert Vaughn and David Janssen in the final role before his death that year. In 1985, he directed The Trip to Bountiful, for which Geraldine Page won the Academy Award for Best Actress. The film also featured his wife, Carlin Glynn who had previously won a Tony Award for her role in 'Whorehouse.' His directing credits additionally include Full Moon in Blue Water (1988), Night Game (1989), Blood Red (1989), Convicts (1991), Arctic Blue (1993), The Only Thrill (1997), Lost Junction (2003), and Whiskey School (2005).
Masterson died at the age of 84 on December 18, 2018, after suffering a fall at his home. He had received a diagnosis of Parkinson's disease 14 years earlier.