The major research data and findings related to aging among persons with developmental disabilities are discussed. Differences between the aging processes noted in the general population and individuals who have developmental disabilities are highlighted. Topics addressed include prevalence of developmental disabilities and mortality rates for individuals with developmental disabilities. The effects of aging on the senses, the neuromusculoskeletal system, and the cardiopulmonary system are presented along with the clinical implications of these changes in individuals with developmental disabilities who are aging.