This report describes the Promoting Success in Zero to Three Services Project, which focused on community-wide efforts in six communities to build systems to provide services for families with infants and toddlers. Part 1 analyzes issues confronted by community stakeholders in their 5-year effort to establish, improve, expand, or maintain services integration. Discussion focuses on availability and accessibility of maternal and child health care services and associated public policy implications. Part 1 also includes an overview of the case study process and presents recommendations to public policy makers and community planners. It identifies four critical issues: (1) a shared vision; (2) the complexity of systems development; (3) data access required for services integration; and (4) leadership and support for developing such integrated systems. Part 2 contains a description of each participating community, including a history of the community's system of services for families with young children, an overview of the current system of services, and a discussion of the community's experience in addressing challenges in services integration. These communities were: Fremont County, Colorado; the Lawndale Community, Chicago, Illinois; Scott County, Indiana; Kent County, Rhode Island; Travis County, Texas; and Snohomish County, Washington. Appendices include an article on the National Parent Policy Advisory Group, the study's methodology, and a listing of case study informants. (Contains 31 references.) (DB)