He is best known for the role of Uncle Rico in Napoleon Dynamite for which he was nominated for the Independent Spirit Award for Best Supporting Male, and recurring character Roger Linus on Lost.

He is also known for his roles in Martin, The Pretender, The Monster Squad, Running Scared, Real Genius, Dream Corp LLC, Get Shorty, and The White Lotus.

He played Lazlo Hollyfeld in Real Genius (1985), Azzolini in Rainbow Drive, Shawn McDermott in the TV series Martin (1992–1994), Ronnie Wingate in Get Shorty (1995), Harvey in The Rundown, and Uncle Rico in Napoleon Dynamite (2004).

He played Martin in the TV show Supernatural in the episodes "Sam, Interrupted" (2010), "Hello, Cruel World" (2011) and "Citizen Fang" (2012).

He played Bob, a former drug addict who operates a safe haven for abused Mexican women, in The Bridge.