- Stage debut was at age 8 as a newsboy in Gypsy in a community theater run by his parents.
- Film debut was in Victimless Crimes, a 1990 direct-to-video thriller.
- Was originally cast as Chandler Bing in Friends, but turned it down in favor of another project. Instead, the role went to Matthew Perry, Bierko's costar on the short-lived CBS sitcom Syndey.
- Made his Broadway-musical debut as Harold Hill in the 2000 revival of The Music Man.
- Played Sky Masterson in the 2009 Broadway revival of Guys and Dolls.
- 2000, Tony — Actor (Musical): Nominee
- 2006, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Nominee
- Pat Bierko — Mother
- Meg Ryan — Ex-significant Other
- Rex Bierko — Father
- Charlize Theron — Ex-significant Other
- Janeane Garofalo — Ex-significant Other
- Attended Boston University, Boston, MA; Northwestern University, Evanston, IL (BA in Speech, 1986)