The first overall goal of this continuation is to determine the relative contribution and specific nature of the neighborhood conditions that are associated with disability in older adults. The second overall goal is to determine the biological mechanisms through which neighborhood conditions lead to increased disability, focusing specifically on hyperactivity of the hypothalamus-pituitary-adrenal (HPA) axis, via salivary cortisol, and inflammatory processes, via interleukin-6 (IL-6) and C-reactive protein (CRP), obtained from blood samples. To accomplish these goals, we propose to continue yearly collection of disability outcome data and obtain blood samples and salivary cortisol from over 7,000 participants. These data will be integrated with a rich set of existing data on personal characteristics, health conditions, and neighborhood factors to test of series of specific hypotheses related to the overall goals.