Building on research in distressed public housing communities, we argue for a new approach to addressing the worst consequences of concentrated poverty and helping families move toward self-sufficiency. We introduce the Housing Opportunities and Services Together (HOST) demonstration, a two-generation, whole-family service model that uses public and mixed-income housing as a platform for intensive, wraparound services. We describe how HOST encapsulates lessons learned from studying federal housing policies, challenges that make reversing chronic disadvantage so difficult, and our theoretical framework for fostering change. We outline HOST's research design in four sites: Chicago, New York, Portland, and Washington, DC.