This study seeks to identify changes in neighborhood and school segregation during the age of rapidly expanding school choice. Prior to 1991, public-school choice was limited. While magnet schools existed and a number of interdistrict transfer programs were in place, few public-school students left their neighborhoods to receive an education. During the past 25 years, the number of public-school choice options has exploded. Today, more than 10% of public-school students attend either a charter school or a magnet school, and many of these schools of choice are concentrated in urban areas. In order to understand how the combination of demographic changes and the expansion of school choice have shaped neighborhoods and schools, this study provides an analysis of levels of racial/ethnic diversity and integration in the 100 most populous U.S. cities and their accompanying school districts. Results of this analysis demonstrate that levels of diversity have risen dramatically in most urban areas as well as in most school districts. Concurrently, an overwhelming majority of cities have experienced increases in neighborhood-level integration while a large majority of schools in their accompanying districts have become increasingly segregated. These divergent patterns in neighborhood and school segregation are cause for alarm and require the immediate attention of policymakers and the public.