(PLEASE KEEP IN WORD, DO NOT PDF) Enter the text here that is the new abstract information for your application. This section must be no longer than 30 lines of text. Chronic kidney disease (CKD) is a major public health problem with high prevalence, high mortality and morbidity, and substantial expense. Black Americans are disproportionately affected by the disease. For example, in the US, Black Americans account for nearly 40% of the population with end-stage kidney disease (ESKD), though they comprise only 13% of the general US population. Despite the persistent disparities for several decades, we have made little progress. Critical knowledge gaps have impeded progress to eliminate the disparities. Our previous award focused on racial disparities in CKD outcomes after the onset of CKD and yielded several key findings. We found that, beginning from the onset of CKD, compared to White patients, Black patients had persistently >2-fold higher risk of progressing to ESKD, but conversely had lower risk of death. Furthermore, at the onset of CKD, Black patients were strikingly 8 years younger than White patients. This earlier age of onset and unexpectedly lower risk of death after CKD onset suggest that differential risk factors and selection bias might have developed in the period before CKD and generated these later differences. Studying risk factors prior to CKD onset (pre-CKD) will be critical to fully understand these disparities. In this project we will extend our work to the period preceding CKD to evaluate upstream determinants such as community-level structural racism and socioeconomic status that contribute to early development of CKD risk factors (downstream factors) among Black adults. In Aim 1, we will develop and examine a range of uni-dimensional and multi-dimensional structural racism measures at the community level corresponding to geographic units such as counties or Public Use Microdata Areas (PUMAs). In Aim 2, we will assess to what extent components of structural racism contribute to the racial differences in development of early CKD risk factors. These aims will be accomplished by analyzing a national cohort of veterans at-risk for CKD. The findings of this project will help us focus on identifying and modifying early CKD risk factors and upstream factors.