In 1984, the National Institute of Mental Health (NIMH) began funding its Child and Adolescent Service System Program (CASSP). In this paper, we present findings from a descriptive study of the experiences of the initial cohort of states to receive CASSP grants, conceived and conducted when the projects were approaching the end of their fifth and final year of NIMH funding. Detailed case studies were conducted of each of the 10 initial cohort projects, and the findings analyzed across projects. Data were collected from three major sources: (1) existing documentation about the projects, (2) site visits to each of the projects, and (3) information from relevant secondary sources. Findings suggest that the initial cohort projects utilized a variety of strategies and encountered a variety of barriers and facilitating factors. The projects generally implemented the intended CASSP program and did so by using a variety of strategies. The projects were judged by stakeholders in their states to have influenced the service systems in their states in the intended directions: toward a more comprehensive system of care that emphasizes community-based treatment; toward better integrated, more collaborative efforts among the state agencies involved; toward a more detailed understanding on the part of system stakeholders of the mental health problems of children and adolescents who have severe emotional disturbances, and of the influence of those problems on the lives of the children and their families; and toward increased involvement by parents and other family members in the care of these children and adolescents.