The National Institute on Aging’s Baltimore Longitudinal Study of Aging (BLSA) is America's longest-running scientific study of human aging. It began in 1958, when gerontology—the study of aging—was still very much in its infancy. Today, the BLSA is world-renowned, having generated thousands of scientific papers and made major contributions to our understanding of what it means to get older. Learn more about the BLSA, including history, research advances, and information on becoming a BLSA participant on the National Institute on Aging website.