This monograph is based on experiences of the national Child and Adolescent Service System Program (CASSP) and describes a plan for developing and implementing community based systems of care for children and adolescents with serious emotional disorders and their families. It draws on examples from state mental health plans to illustrate planning approaches to systems change. Stressed is the need for the system of care to be child centered, family focused, and community based. The introduction identifies desirable system components and the requirements of the Mental Health Services Plan and its 1990 Amendments. The first chapter identifies principles of effective planning such as the involvement of key stakeholders. The second chapter provides various state definitions of the target population, information on population size, service requirements, and current system assessment. Specific values and principles of CASSP are identified next. The fourth chapter examines the ways by which various states have addressed goals and objectives including structural change objectives relating to infrastructure, financing, and interagency collaboration. Specific strategies, resources and responsibility centers are identified in the fifth chapter. The last two chapters consider planning and progress reporting format and program evaluation methods. A list of technical assistance materials is appended. Includes 16 references. (DB)