The American College of Physicians (ACP) founded National Internal Medicine Day in 2019 to recognize the contributions of internal medicine specialists and subspecialists who are united by a commitment to excellence around the world. ACP represents 163,000 internal medicine physicians (internists), related subspecialists, and medical students across the globe, and is the largest medical-specialty society in the world. ACP and its physician members lead the profession in education, standard-setting, and the sharing of knowledge to advance the science and practice of internal medicine.