Dr. Greenblatt is a graduate of Long Island University, where he obtained his Bachelor of Science in 1975. He then obtained his medical degree from Keck School
of Medicine of the University of Southern Califonia. He then completed 3 years of Residency in Internal Medicine at North Shore University, followed by a Gastroenterology fellowship at the Medical College of Pennsylvania. He is a fellow of the American College of Gastroenterology and the American College of Physicians.
He is board certified in Internal Medicine and Gastroenterology. He has previously taught at St. Elizabeth Hospital, which is currently known as Trinitas Hospital. He has held the position of Chairman of the Department of Gastroenterology at Elizabeth General Medical Center from 1990-2001, and Chairman of the Department of Gastroenterology at Trinitas Hospital from 2001-2010. He has also held the position as Chairm