Acting

2014

(5 episodes) as George Feeny

2005		The Closer (2 episodes) as Commissioner Andrew Schmidt
2005		Grey's Anatomy (5 episodes) as Craig Thomas

2004

(1 episode) as Judge Milton Brody

2003

(1 episode)

2002

(1 episode) as Robot Pilot (voice)

2001

(1 episode) as Dr. Douglas

1998

(1 episode) as Phillip Waldscott

1995

(1 episode) as George Feeny

1994		The American Revolution (6 episodes) as John Adams
1994		Touched by an Angel (1 episode) as George (1 episode) as Whit Russell

1993

(158 episodes) as George Feeny

1989

(2 episodes) as KITT (voice)

1982		St. Elsewhere (137 episodes) as Mark Craig
1982		Knight Rider (84 episodes) as K.I.T.T. (voice)
1982		Faerie Tale Theatre (1 episode) as Narrator (voice)

1980		Freebie and the Bean (9 episodes)
1980		Galactica 1980 (2 episodes) as Norman Blore

1979		Trapper John, M.D. (1 episode)
1979		Hart to Hart (1 episode)
1979		Blind Ambition (4 episodes) as G. Gordon Liddy

1978		Diff'rent Strokes (1 episode)
1978		Grandpa Goes to Washington (1 episode)

1977		The Incredible Hulk (1 episode) as Dr. John Bonifant
1977		Soap (1 episode) as Heinrich Himmel

1976		Quincy, M.E. (3 episodes)
1976		The Nancy Walker Show (12 episodes) as Kenneth Kitteridge
1976		The Adams Chronicles (13 episodes)

1975

(1 episode) as Harry Boyle

1974		Kolchak: The Night Stalker (1 episode) as Police Lt. Jack Matteo
1974		The Rockford Files (1 episode) as Gary Bevins (1 episode) as Thomas Caine

1973

(2 episodes)

1971		McMillan and Wife (1 episode) as Commander Campbell
1971		Cannon (1 episode)

1970

(2 episodes)

1968		The Good Guys (1 episode)
1968		The Mod Squad (1 episode)

1967		Judd for the Defense (1 episode)
1967		Ironside (1 episode)
1967		Captain Nice (15 episodes) as Carter Nash

1966

(1 episode) as Tony Webb

1961

(1 episode) as Mike Herman (1 episode) as Malloy

1958

(1 episode) as Harry Culverin

1956

(1 episode) as Self - Performer

1951

(1 episode) (1 episode) as John Quincy Adams

Directing

1982

(1 episode) … Director