Coming off a 1994 Memorial Cup championship with the Kamloops Blazers of the WHL, Baumgartner was chosen by the Washington Capitals in the first round, 10th overall of the 1994 NHL Entry Draft.

Upon being drafted, he returned to the WHL and joined future NHLers Darcy Tucker, Shane Doan and Jarome Iginla to capture a second consecutive Memorial Cup in 1995.

After playing the majority of his tenure in Washington with the Capitals' American Hockey League affiliate, the Portland Pirates, he was traded to the Chicago Blackhawks on July 20, 2000, for Rémi Royer.

[1] After one season with the Canucks, he was left unprotected for the 2003 NHL Waiver Draft and selected by the Pittsburgh Penguins on October 3, 2003.

As the Moose began play at the newly opened MTS Center in 2004–05, Baumgartner earned the distinction of scoring the first ever professional goal at the arena, on November 17, 2004.

Following Baumgartner's breakout season, he became an unrestricted free agent, and on July 1, 2006, he signed a two-year deal with the Philadelphia Flyers.

Baumgarter retired from hockey at the end of the 2011–12 season with the Chicago Wolves and was named an assistant coach of the team.