Dr Mojica received his BA in Biology from the University of Chicago. He received his MD from Columbia University's College of Physicians and Surgeons and completed training in Internal Medicine in the Columbia campus of the New York Presbyterian Hospital, where he served as a Chief Resident. Dr Mojica completed fellowship training in the Harvard Pulmonary and Critical Care Medicine Program and subsequently sought subspecialty training in Sleep Disorders. He completed a Sleep Medicine Fellowship in the Beth Israel Deaconess Medical Center site of the Harvard Medical School's Division of Sleep Medicine.  He is the current Vice-Chief and Clinical Director of Pulmonary & Critical Care Medicine at Massachusetts General Hospital.