In the thirty years since Massey and Denton's American Apartheid, sociological scholarship on segregation has proliferated, calling attention to the ways in which the social geography of the United States both drives and is shaped by racial and economic inequality. More recent work has focused on the role that institutional actors play in the reproduction of residential segregation and its disparate impacts on communities of color. In this article, we describe different conceptualizations of segregation and how it has been used as a tool for exclusion and exploitation. We review literature on housing and institutional marginalization, highlighting the historical and contemporary mechanisms that perpetuate inequality and necessitate continued research on this topic. We conclude with a discussion of additional considerations and opportunities for future research. Expected final online publication date for the Annual Review of Sociology, Volume 50 is July 2024. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.