In 2005, AuCoin appeared as Octavius in a Broadway revival of Julius Caesar, which starred Denzel Washington. AuCoin has appeared in numerous other Off-Broadway stage productions, including Manhattan Theatre Club’s productions of Of Good Stock and Long Lost, and Signature Theatre’s 2014 revival of A. R. Gurney’s The Wayside Motor Inn, directed by Lila Neugebauer, which won him, and the rest of the cast, a special Drama Desk Award for “Outstanding Ensemble”. Other Off Broadway productions include 2008’s premiere of Ernest Hemingway’s The Fifth Column, 2009’s Jailbait, by Deirdre O’Connor, directed by Suzanne Agins, 2010’s Happy Now?, by Lucinda Coxon, the 2013 premiere of Tanya Barfield’s The Call, directed by Leigh Silverman in a joint production by Primary Stages and Playwrights Horizons, He recently starred in two La Jolla Playhouse productions; J. T. Rogers’ Blood And Gifts, directed by Lucie Tiberghien, and Arthur Kopit and Anton Dudley’s world premier A Dram Of Drummhicit, directed by Christopher Ashley. AuCoin was a member of the Oregon Shakespeare Festival acting company in the early 1990s.

His first major film role came in 2007, where he played State Department official Ellis Leach in The Kingdom. In 2009’s Julie & Julia, AuCoin played one of the executives for the Houghton Mifflin publishing company who declined to publish Julia Child’s soon-to-be-legendary cookbook. More recently he has appeared in Complete Unknown, starring Rachel Weisz, and Barry Levinson’s The Wizard of Lies, starring Robert De Niro, Drunk Parents, starring Alec Baldwin and Salma Hayek, and the upcoming films The Good Huuse, starring Sigourney Weaver and Kevin Kline, and False Positive, starring and written by Iliana Glazer.

For the 2012 presidential election, NPR’s Planet Money team cast AuCoin as their “Fake Presidential Candidate” to give voice to “major economic policies they could all stand behind.”