Dr. Marc L. Greenwald is a colon and rectal surgeon in Great Neck, New York and is affiliated with multiple hospitals in the area, including Long Island Jewish Medical Center at Northwell Health and North Shore University Hospital at Northwell Health. He received his medical degree from Albert Einstein College of Medicine of Yeshiva University and has been in practice for more than 20 years. Dr. Marc L. Greenwald has expertise in treating colonoscopy, colon removal, among other conditions - see all areas of expertise. Dr. Marc L. Greenwald accepts Medicare, Aetna, Humana, Cigna, Blue Cross - see other insurance plans accepted.