Dr. Gregory D. Mackay is a gastroenterologist in Vero Beach, Florida and is affiliated with Cleveland Clinic Indian River Hospital. He received his medical degree from Sidney Kimmel Medical College at Thomas Jefferson University and has been in practice for more than 20 years. Dr. Gregory D. Mackay has expertise in treating colonoscopy, upper gi endoscopy, among other conditions - see all areas of expertise. Dr. Gregory D. Mackay accepts Medicare, Aetna, Cigna, Blue Cross, United Healthcare - see other insurance plans accepted. Dr. Gregory D. Mackay is highly recommended by patients.