Dr. Onsager received his bachelorâ€™s degree in Bio chemistry, History and Sociology of Science from the University of Pennsylvania. He completed medical school at Rush Medical College and a general Surgery Residency at the Medical College of Wisconsin Affiliated Hospitals. He completed Fellowship training in cardiothoracic surgery at the University of Wisconsin Hospital and Clinics where he also completed a Thoracic Organ Transplantation Fellowship. An Advanced Fellowship in Adult Cardiac Surgery was completed at the University of Chicago Medical Center. He is a Clinical Assistant Professor in the Division of Cardiothoracic Surgery at Loyola University Medical Center.
Dr. Onsager is happily married. He enjoys tennis, skiing and flying. He is an instrument-rated pilot.