Movies
* The Thing (1982)
* The Verdict (1982)
* Splash (1984)
* The Sure Thing (1985)
* The Jewel of the Nile (1985)
* Three Men and a Baby (1987)
* The Accidental Tourist (1988)
* The Freshman (1990)
* The Santa Clause (1994)
* The Postman (1997)
* The Majestic (2001)
* The Emperor's Club (2002)
* The Greatest Game Ever Played (2005)
* The Informant! (2009)
* Captain America: The First Avenger (2011)
* The Judge (2014)
Television
* Hill Street Blues (1981-1987) - recurring role as Detective Stan Jablonski
* The Equalizer (1985-1989) - recurring role as Detective Marcus
* L.A. Law (1986-1994) - recurring role as Judge Edward Lehman
* The Practice (1997-2004) - recurring role as Judge Milton Schiffman
* The West Wing (1999-2006) - recurring role as Senator Arnold Vinick
* The Good Wife (2010-2016) - recurring role as Judge Robert K. Foster
* The Americans (2013-2018) - recurring role as Philip's therapist, Dr. Wolfe
* House of Cards (2013-2018) - recurring role as the President's Chief of Staff
* The Blacklist (2013-present) - recurring role as the Attorney General
* Madam Secretary (2014-2019) - recurring role as the Secretary of Defense
This is just a small sample of Richard Masur's extensive filmography. He has also had numerous guest appearances on various TV shows and has been involved in several theatrical productions.
You can find more information on his career by searching online databases like IMDb or the Internet Movie Database.