Don E. Detmer has served as President and Chief Executive Officer of the American Medical Informatics Association (AMIA) for the past five years, helping to set a course for the organization and demonstrating remarkable leadership as AMIA has evolved into a vibrant and influential professional association. On the occasion of Dr. Detmer's retirement, we fondly reflect on his professional life and his many contributions to biomedical informatics and, more generally, to health care in the U.S. and globally.