Racial inequalities in chronic kidney disease (CKD) have been well-documented but are not well-understood. Recent research suggests an important role for genetics such as the high risk variants of the gene, APOL1, encoding the apolipoprotein L1, present only in persons of African descent. However, research also points to neighborhoods as an important source of health inequalities and clarifying its role is critical as neighborhoods are neither random nor naturally-occurring and are amenable to change. In fact, it may be that neighborhood environments may result in CKD through their interaction with genetic susceptibility. Using three complementary cohorts, this study will examine the interactive effects between specific neighborhood characteristics and APOL1 on longitudinal measures of CKD.