Project Summary Housing is a critical social determinant of health and key contributor to racial/ethnic health disparities in the US. In the context of rising housing costs, a recent recession, and the COVID-19 pandemic, experiences with housing instability such as foreclosure, eviction, and homelessness are a serious and growing public health concern. Black and Latino households are at an elevated risk of encountering these adverse housing transitions compared with their White counterparts. Moreover, the subsequent exposures to heightened psychosocial stress and financial strain have been shown to be particularly detrimental to Black and Latino physical and mental health. Despite policy efforts to increase homeownership among Black and Latino households, homeownership gaps remain large and have been widening. And given that homeowners are more advantaged than renters, including having access to own household wealth and wealthier kin networks, owners may be better equipped to sustain spells of housing instability over time and should be integral to understanding how health disparities manifest later in life. Yet, we know little about the long-term health consequences of housing instability, and how these stressful experiences contribute to racial/ethnic disparities in late-life health. In addition, much of what is known about wealth and late-life health rests upon research limited to Black-White comparisons, as well as work that has not considered the roles of extended kin financial resources and adverse housing transitions. To remedy these issues, this project will leverage nationally representative longitudinal data from the Panel Study of Income Dynamics (PSID) to evaluate a theoretical model of housing instability and late-life health among Black, Latino, and White households. The unique features of the PSID allow us to: (1) estimate the effects of housing instability on late-life health, and whether the effects vary by racial/ethnic group and housing tenure; (2) determine whether racial/ethnic disparities in exposure to housing instability mediate racial/ethnic health disparities later in life; and (3) determine whether extended-family wealth moderates the effects of housing instability on late-life health, and whether the health effects vary by racial/ethnic group and housing tenure. This project will complete these three aims using a counterfactual framework that produces robust causal estimates of housing instability over time on late-life health outcomes, including cognitive functioning, psychological distress, self-rated health, and functional limitations. Estimates will come from marginal structural models with inverse-probability-treatment weights, which will allow for time-varying confounders that overcome challenges facing conventional regression techniques (e.g., selection bias, reverse causality)—a key innovation of this project.