The objective of this request to the Robert Wood Johnson Foundation is to obtain support to produce a focused review and critical summary of the relevant literature and empirical datasets examining the contributions of both race and ethnicity to physical and mental health of individuals and groups classified as ?Black? in the United States. There is a vast amount of research documenting racial disparities in health, as well as streams of research aimed at developing conceptual models. These bodies of work shed light on an array of social, psychological, and environmental factors influencing racial and ethnic disparities in a range of health related outcomes, including life expectancy, morbidities, mortality rates, as well as how these patterns vary across the life course. Generally, these literatures focus on Black-white differences. More recently, there is a growing recognition of the significant and meaningful diversity within the U.S. Black population based on factors related to nativity, immigration status, and skin tone. Using a range of strategies, the main foci of the proposed project would be to investigate the existing evidence regarding how and when disaggregating the category of Black race through identifying specific variables of interest leads to varying patterns of results.