Gaines has appeared in a number of films and television shows, including
Fame,
Frasier,
L.A. Law,
Law & Order, and
Piece of Cake, but his most notable television role was as Mark Royer, who married
Valerie Bertinelli's Barbara Cooper on TV's
One Day at a Time. Gaines appeared in the final three seasons of the show. He also portrayed Coach Brackett in the 1981 movie ''
Porky's, Lt. Ring in the 1986 film Heartbreak Ridge and Jason in The Sure Thing'' (1985). Gaines is a voice actor, and is credited with recording several
audiobooks. He has appeared on the
Broadway stage, in both musicals and plays, for which he has won four Tony Awards. His first Broadway play was
The Heidi Chronicles in 1989. He has appeared in the musicals
She Loves Me (1993),
Company (1995), and
Contact (2000). Other plays have included the 2010 revival of
Driving Miss Daisy,
The Columnist (2012), and the Broadway revival of
An Enemy of the People in 2012. He appeared in the 2008 revival of
Gypsy as Herbie, and won the
Tony Award for Best Featured Actor in a Musical. He has appeared
Off-Broadway, starting in 1978 with
Spring Awakening and recently
The Grand Manner by A. R. Gurney at
Lincoln Center in 2010. In regional theatre, Gaines appeared in
Our Town at the
George Street Playhouse, New Jersey, in April 2014. ==Awards and nominations==