Prospective panel study of health and aging in Mexico, with national and urban/rural representation. The baseline survey was conducted in the Summer of 2001, and a follow-up is planned for the Spring-Summer of 2003. Collaborative effort among researchers from the Universities of Pennsylvania, Maryland, and Wisconsin in the U.S., and the Instituto Nacional de Estadistica, Geografia e Informatica (INEGI) in Mexico. Data is available for 2001 and 2003.