Taye Diggs, Tim Daly, Amy Brenneman, Chris Lowell, and Audra Mc Donald were cast in the spin-off, Private Practice.Walsh returned to Seattle Grace as a special guest star for episode thirteen in Season 4 and episodes 15 and 16 in Season 5 of Grey's Anatomy. She later studied acting at the University of Arizona and at Chicago's Piven Theatre Workshop before moving to New York City and joining the comedy troupe, Burn Manhattan, supporting herself by waitressing.
In 2013, Walsh appeared in Full Circle, a 10-episode ensemble drama series created by Neil La Bute and airing on Direc TV's Audience Network channel.
After playing Cathy Buxton in the Homicide: Life on the Street episode "Stakeout" in 1996 and Navy Lieutenant Kirstin Blair in the Law & Order episode "Navy Blues", her first major television appearance was in 1997, when she appeared on The Drew Carey Show as Drew Carey's love interest, Nicki Fifer.
She wore a fatsuit in some episodes of the show, as the Nicki character was a formerly obese woman who lost weight and slowly started to gain it back.
She went on to portray Carol Nelson in HBO's The Mind of the Married Man television series, and played Norm Macdonald's romantic interest in the sitcom The Norm Show.
Walsh also made a guest appearance on CSI: Crime Scene Investigation as Mimosa, a transsexual.
In New York, Walsh was a member of the improvisational comedy troupe Burn Manhattan and the New York City Players theater ensemble.