Previously, Bagley had a recurring role as Principal Toby Pearson on the American sitcom Teachers, and as Peter in the Netflix series Grace and Frankie.

Although he retired from the theatre's Main Company in the mid 1990s, Bagley still comes back regularly to perform in The Groundlings' all-improv show Cookin' with Gas.

After guest appearances on Diagnosis: Murder and Seinfeld, he landed his first regular role on the Showtime series Howie Mandel's Sunny Skies.

He has guest starred on such shows as Seinfeld, Wings, Dharma & Greg, According to Jim, Curb Your Enthusiasm, The X Files, Suddenly Susan, ER, Ellen, 3rd Rock from the Sun, The Nanny, and Desperate Housewives.

In addition to his work in independent films, Bagley has appeared in big-budget movies like The Mask, Austin Powers: The Spy Who Shagged Me and Knocked Up.