Harriet Kotsoris earned her MD at the University of Rochester in 1980. She did her residency in Internal Medicine at New York Hospital (now known as Weill-Cornell Medical Center) between 1980-1983. She did her residency in Neurology at New York Hospital between1983-1986. She was the Chief Resident between1985-86. She is board certified in Internal medicine and Neurology. She had a private practice in Neurology and was the Attending in Neurology at Stamford Hospital, Stamford, CT, affiliate of Columbia Presbyterian, for nearly 2 decades. She has been the Chief Scientific Officer for Lyme Research Alliance, formerly Time for Lyme from 2007 to the present.