He received a medical degree from the University of Minnesota, completed an internship and additional general surgery training and a residency in orthopedic surgery at UCSF and completed a hand surgery fellowship under Dr. Jack Tupper in Oakland. He spent the following two years as an orthopedic research physician in Switzerland at the University of Bern and the Laboratory for Experimental Surgery. Masem obtained his training in hand, upper extremity and microsurgery as a clinical and research fellow at Massachusetts General Hospital and Harvard Medical School.