From 1986 to 1989, he worked at the Empire Diner. He went to
Los Angeles to help Fontana move into his house. While dining at a restaurant on the day after arriving in LA, a casting director and friend of Fontana's asked Tergesen if he was an actor. "He told me there was a part in this movie and at that time, I couldn't imagine what it could be," Tergesen told the
L.A. Times. He then appeared in ''
Wayne's World (1992) and Wayne's World 2 (1993), in the 1994 series Weird Science as Chester "Chett" Donnelly, and had a recurring role in the first season of Homicide: Life on the Street''. He portrayed
Tobias Beecher on
HBO's
Oz in 1997, a critically acclaimed role he played until the series ended in 2003. His film credits include
Shaft,
Monster,
The Forgotten,
The Texas Chainsaw Massacre: The Beginning,
Cast A Deadly Spell and
Wild Iris. He has made several appearances in TV shows such as
ER,
Rescue Me,
CSI: Crime Scene Investigation,
Criminal Minds,
The 4400,
House,
Law & Order and two of its
spin-offs,
Law & Order: Criminal Intent and
Law & Order: Special Victims Unit. He played a murderous
Navy SEAL,
Andrew Larrick, in Season 2 of
The Americans on the
FX television network. He played an
Alcoholics Anonymous sponsor in the second season of
Desperate Housewives, becoming romantically involved with
Bree Van de Kamp. He appeared in the
USA Network series
Royal Pains and in Seasons 4–5 of the
Lifetime series
Army Wives. He played Evan Wright in the HBO mini-series
Generation Kill. He has appeared on stage in the
Off-Broadway productions of
Long Lost (2019) by
Donald Margulies and
Rapture, Blister, Burn in 2012 at Playwrights Horizons, among others. ==Personal life==