Born in New York City, New York, United States, Hoffman's earliest works either were mounted in small, experimental off-off-Broadway theaters in New York City or remain unproduced.

It was not until 1985 that he achieved critical acclaim and public recognition when the Broadway-theatre production of his play, As Is, one of the first plays to focus on AIDS, opened in New York City at the Lyceum Theatre, where it ran for 285 performances. Hoffman won a Drama Desk Award for Outstanding Play (1985) and an Obie Award (1984-85 for Playwriting ) and nominations for a Tony Award for Best Play (1985). The following year, he adapted the work for a television production directed by Michael Lindsay-Hogg.

In 1991, Hoffman was commissioned by The Metropolitan Opera Company to write the libretto for The Ghosts of Versailles first produced in celebration of the company's centennial. A 1993-televised production starred Teresa Stratas, Renée Fleming, and Graham Clark. Hoffman earned an Primetime Emmy Award nomination for Outstanding Individual Achievement in Classical Music/Dance Programming.

As an editor at Hill and Wang, Hoffman promoted the careers of Lanford Wilson, Tom Eyen, and Joe Orton, among others, by including their plays in either his New American Plays series or his anthology, Gay Plays: A First Collection.

Hoffman currently is an Associate Professor of Theatre at Lehman College at The City University of New York .

(Year indicated is when first produced)

• As Is (1985)
• A Book of Etiquette (1978)
• The Cherry Orchard, Part II (1983)
• Children's Crusade (1972)
• Cornbury (with Anthony Holland) (1979)
• From Fool to Hanged Man (1972)
• Giles De Rais (1975)
• Good Night, I Love You (1966)

• Gulliver's Travels (1978)
• Incantation (1967)
• Luna - (1970)
• A Quick Nutbread to Make Your Mouth Water (1970)
• Saturday Night at the Movies (1966)
• Shoe Palace Murray (1978)
• Thank You, Miss Victoria (1965)
• xxx (aka Nativity Play) (1969)

• Daytime Emmy Award nomination in 1992 for Outstanding Drama Series Writing Team - One Life to Live (as part of a 15-member team)

• Writers Guild of America Award (Best Writing, One Life to Live (1996)