Beginning in 1990, he had a recurring guest role on Northern Exposure playing the angry, paranoid Adam, for which he received an Emmy nomination.

In 2009, he portrayed villain Ethan Zobelle, a white separatist gang leader, in Sons of Anarchy and Principal Ed Gibb in 8 Simple Rules (2003–2005).

[2] Arkin joined his parents singing in the children's music group the Baby Sitters, along with Lee Hays and Doris Willens.

[6] He has since appeared in numerous television series, including: A Year in the Life (1988); The Twilight Zone (1986); Northern Exposure (CBS, 1990–1995), in which he played the mercurial barefooted chef Adam; and Chicago Hope (CBS, 1994–2000); two Law & Order episodes (as jewelry store owner George Costas in "Self Defense," Season 3, 1992, and as a district attorney named Charles Graham in "Red Ball," Season 16, 2005); Picket Fences (Season 2, Episode 13); The West Wing (1999) (as trauma specialist and psychiatrist Dr. Stanley Keyworth); Frasier (as an obsessive fan of Frasier, for which he was nominated for a Primetime Emmy Award for Outstanding Guest Actor in a Comedy Series); Boston Legal; Baby Bob; Monk; and 8 Simple Rules for Dating My Teenage Daughter (2002).

He played a white separatist leader named Ethan Zobelle during the second season of the series Sons of Anarchy.

[7] In 2011, he appeared in a Season 7 episode of The Closer ("To Serve with Love"), and portrayed mob boss Theo Tonin on Justified as well as an FBI agent in The Chicago Code.

[9] In addition, he is known for his directing work, including episodes of Grey's Anatomy, Boston Legal, The Riches, Dirt, Ally McBeal, Sons of Anarchy, The Blacklist, Justified, and Masters of Sex.