Dr. Hagan is a member of the American Society of Plastic Surgeons, the American Association for Hand Surgery, the American Society For Peripheral Nerve, the American Society for Reconstructive Microsurgery, the Association of Extremity Nerve Surgeons, the American Headache Society, and the American Diabetes Society.

Dr. Hagan received his MD from Saint Louis University School of Medicine. He received his general surgery training at The Lahey Clinic in Boston, Massachusetts and his plastic surgery training at The Lahey Clinic and Harvard Medical School hospitals. He continued his education as a fellow at Harvard Medical School in Boston, Massachusetts specializing in hand and microsurgery. Upon returning to the Midwest, he completed a craniofacial fellowship at Washington University in St. Louis, MO.