On television, Lewis starred for five seasons on the NBC sitcom NewsRadio, followed by Three Sisters and the WB animated comedy Mission Hill.

More recently, she made guest appearances on Surviving Suburbia, ABC's Grey's Anatomy, Disney Channel's Sonny with a Chance as Ms. Bitterman, The Middle as Ms. Barry, and FX's Dirt.

She recurred as Erica on Modern Family, Mrs. Chadwick in Making History, Dr. Chapman in Still the King, Miss Moffett in Angie Tribeca, and Marie Mortel in The Blacklist.

Aside from Mission Hill, her voice acting career includes characters in Justice League Heroes, Rugrats Pre-School Daze, King of the Hill, Hercules: The Animated Series, An Extremely Goofy Movie, Finding Nemo, Phineas and Ferb, and Justice League: The New Frontier.

The Musical, Damn Yankees, Chicago, The Crucible, and she was the final actress to play Countess Lily in Anastasia.

Lewis won the 2007 Ovation Award for Best Featured Actress in a Musical for the world premiere of Michael John LaChiusa's Hotel C'est L'amour.

The musical was re-imagined by Ashman's partners Marsha Malamet and Dennis Green and performed one night only at Los Angeles's Hayworth Theatre as part of the Bruno Kirby celebrity reading series.