Background
Siff was born in The Bronx, New York City. Her father is Jewish, and Siff identifies as "half Jewish".
Siff was born in The Bronx, New York City. Her father is Jewish, and Siff identifies as "half Jewish".
She is an alumna of The Bronx High School of Science and of Bryn Mawr College, where she majored in English and graduated in 1996. She later completed an Master of Fine Arts in acting at New York University"s Tisch School of the Arts Graduate Acting Program.
She is best known for her television roles as department store heiress Rachel Menken Katz on the Administrative Management College drama Mad Men and Doctor Tara Knowles-Teller on the Forex drama Sons of Anarchy. She also had roles in the films Push (2009) as Teresa Stowe and Leaves of Grass (2010) as Rabbi Renannah Zimmerman. Siff worked extensively in regional theater before acting in television
Siff started appearing in television series in 2004.
She appeared as an Alcoholics Anonymous speaker during an episode of Rescue Maine in Season 2. She also had roles on Law & Order: Special Victims Unit, Grey"s Anatomy, and Law & Order.
She also appeared in Nip/Tuck during that time, before being cast as Doctor 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)."
She has appeared in such films as Then She Foundation Maine (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.