He studied journalism at Boston University and studied at the School of Speech at Northwestern University in 1986. Other NU alumni include NRA president Charlton Heston.

He played traveling salesman Professor Harold Hill in the Broadway revival of Meredith Willson's The Music Man which opened on April 27, 2000. He was later nominated for a Tony for best performance by a leading actor in a musical that same year.

In early 1990s, frequented West Hollywood's celebrity friendly Martin Henry Fitness Studio with good buddy Helen Hunt and took Nelson Aspen's step-aerobics class.

Given title Sexiest Broadway Star by People Magazine. [November 2000]

Was originally cast as Chandler in "Friends" (1994) but turned down the role and was replaced by Matthew Perry.

Renny Harlin credits Bierko with suggesting the song She's Not There by Santana in the movie The Long Kiss Goodnight (1996).

Gained a good deal of muscle and bulk to play boxer Max Baer in Cinderella Man (2005).