Dr. Casimo graduated cum laude from Colgate University then earned his medical degree at the University of Vermont College of Medicine in Burlington, VT. He completed an internship and residency in Internal Medicine at the University of Pittsburgh School of Medicine. He later served as a gastroenterology fellow at Genesee Hospital at the University of Rochester School of Medicine.

Before joining Vancouver Clinic in 1998, Dr. Casimo was in private practice in Vancouver.