The aging of the U.S. population has led many organizations to call for an increase in the amount of clinical geriatrics training in medical education. A subcommittee of the American Geriatrics Society's Education Committee was assigned the task of defining core competencies for geriatrics education in medical schools. The subcommittee reviewed the available literature, surveyed selected programs in geriatrics education, and sought input from experts in geriatrics education. They then defined the core knowledge, attitudes, and skills students must develop to care for older people. This article summarizes these core competencies, which medical educators may find useful in developing new curricula on aging or in evaluating existing curricula.