Teddy attended the University of Texas Southwestern Medical Center. She completed her surgical residency at George Washington University Medical School and her fellowship at Mayo Clinic in Florida. As an attending physician, Teddy worked at Columbia, but after her best friend and lover Allison was killed during the collapse of the second tower on September 11, 2001, she left and joined the army, meeting trauma surgeon Owen Hunt (Kevin McKidd) during her tour in Baghdad.