After "MADtv", Flanagan's most notable television role was the recurring role of Lois Sadler on the drama series "Mad Men, "on which she appeared for the first three seasons from 2007 to 2009." "She has also appeared on "Curb Your Enthusiasm", "The Practice", "ER", and a recurring role on "You've Got a Friend". She partnered up with the team behind Ask a Ninja to create a video podcast called "Hope is Emo". Flanagan played the role of Hermione Granger in the 2007 film, "Epic Movie". She later appeared as Ugly Betty/Oracle in the "sequel" "Meet the Spartans", and in "Disaster Movie" played Juney, a parody of "Juno", and Hannah Montana/Miley Cyrus. She also appeared in Seltzer and Friedberg's 2010 project, "Vampires Suck", as 'Eden Sullen'. With the release of Best Night Ever in 2013, she became the most recurring actress in Jason Friedberg and Aaron Seltzer films. She posed nude in the August 2010 issue of Playboy.