Louis Marchioli, M.D., built one of the largest private medical practices in both pediatric and adult allergy and immunology in Southern California. After a fellowship in allergy and immunology, his patient roster included many severe adult and pediatric asthmatic patients. Because of the large number, he was able to stratify patient phenotypes early on, enabling more precise and beneficial treatments. With the advent of Health Management Organization medicine, he made the decision to remain in private practice in order to give patients the best quality of care. The decision required returning to the speciality of internal medicine and enhancing patient and family contact so that they could understand and be given the proper advancements in medicine with less third-party interference. Dr. Marchioli has served as president of Whittier Academy of Medicine, LA County Medical Association East District and has served on numerous boards and ministries. He has received multiple honors and awards for his service and quality of practice. Dr. Marchioli earned his M.D. from Saint Louis University and his B.S. in Chemistry from the University of Notre Dame.