In 2001, she was cast as Dr. Elliot Reid in the NBC comedy series "Scrubs" and she would be a cast member for all nine seasons until the series ended its run in 2010. She has appeared in several feature films, including "Ernest Goes to School" and "Cake". She appeared in Channel 101's "The 'Bu" with The Lonely Island, a parody of the hit show "The O.C.", but was credited as "Pamela Fenton". In 2007, she appeared as a supporting character in "Chaos Theory", which starred fellow Canadian Ryan Reynolds. In 2008, Chalke became the spokesperson for a line of women's underwear by Hanes that included a series of commercials directed by her "Scrubs" co-star Zach Braff. In 2008 and 2009, she made appearances in the CBS sitcom "How I Met Your Mother" as Stella Zinman. In early 2011, she starred in the CBS television series "Mad Love", a romantic comedy which debuted as a midseason replacement and was cancelled after only one season was produced.