- At age 12, she made her stage debut playing a boy in a production of Amahl and the Night Visitors.
- Studied acting at William Esper Studio in New York.
- Made her feature-film debut in 1994's A Miracle on 34th Street.
- Breakout movie performance was in 1997's Private Parts, playing Howard Stern's wife.
- Performed for three New York theaters: the Atlantic Theatre Company, Alice's 4th Floor and Naked Angels.
- Acted with her brother, Will McCormack, in the 1997 independent film comedy Colin Fitz.
- Her Tony-nominated turn as Gretchen in the 2008 play Boeing-Boeing drew praise from the New York Times for her "glorious Olympian strut" and "take-no-prisoners stance."
- During her run as Mary Shannon on the cable crime drama, In Plain Sight, her character's pregnancy was written into the story. "It's nice I think for women to see an actual pregnant person on TV," she explained; she gave birth to her third daugter in 2011.
- 2008, Tony — Actress (Featured Role--Play): Nominee
- 2004, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Nominee
- 2005, Screen Actors Guild Awards — Outstanding Performance by an Ensemble in a Drama Series: Nominee
- William McCormack — Father
- Michael Morris — Husband
- Bridget — Sister
- Lillian Morris — Daughter
- Norah McCormack — Mother
- Will McCormack — Brother
- Margaret Morris — Daughter
- Rose Morris — Daughter
- Trinity College, Hartford, Connecticut, United States (BA in Comparative Arts, 1991)