Nationwide, place-based initiatives aiming to improve school and community outcomes are in the midst of neighborhood demographic change. We explore this issue through a case study of the Mission Promise Neighborhood (MPN). We discuss how the social and educational context of MPN poses several challenges to implementing Promise Neighborhood reforms. Drawing on enrollment and residence data from San Francisco Unified School District (SFUSD) and the U.S. Census, we show that the MPN service population extends beyond the geographic boundaries of the neighborhood and includes two primary groups of increasingly unequal social and economic status: working-class Latinos and high-income Whites. We situate these findings within the context of SFUSD's school assignment policy and gentrification in the Mission neighborhood. We conclude that complexities in the MPN service population have significant implications for MPN service provision and the definition of a "neighborhood community." These implications apply to other place-based initiatives experiencing neighborhood demographic change.