<P> Siff worked extensively in regional theater before acting in television . She won a Barrymore Award for Excellence in Theater in 1998 for her work in Henrik Ibsen's Ghosts at Lantern Theater Company . </P> <P> Siff started appearing in television series in 2004 . She appeared as an Alcoholics Anonymous speaker during an episode of Rescue Me in Season 2 . She also had roles on Law & Order: Special Victims Unit, Grey's Anatomy, and Law & Order . </P> <P> She played Rachel Menken Katz on the series Mad Men from 2007 to 2008, which earned her a nomination, along with the rest of the cast, for a Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series . She also appeared in Nip / Tuck during that time, before being cast as Dr. Tara Knowles on Sons of Anarchy in 2008 . In the closing scene of the Sons of Anarchy episode "John 8: 32," Siff sang the song "Lullaby for a Soldier (Arms of the Angels)." </P> <P> She has appeared in such films as Then She Found Me (2007) as Lily, Push as a psychic surgeon (called a Stitch) named Teresa Stowe, sent to help Nick (played by Chris Evans), Funny People (2009) as Rachel, Leaves of Grass (2010) as Rabbi Renannah Zimmerman, and Concussion (2013) as Sam Bennet . She appears in the 2016 Showtime series Billions . She started in an independent indie film called A Woman, A Part as well . (2016) </P>

Who plays the doctor in sons of anarchy