This paper introduces a framework for conceptualizing a system of care for children and youth with severe emotional or behavioral disorders built on a child development perspective. The approach focuses on developmental transitions which all children and youth experience. Such transitions include entry into school, negotiating the challenges associated with the teen years in modern society, and emancipation from home. The first tier of the model includes a continuum of services that focuses on service and policies which promote the health development of children and youth while attempting to prevent serious mental health problems before they arise. Early identification and appropriate referral become crucial tasks. The second tier of this model includes the continuum of services for those children who have received clinical diagnosis. This continuum would include such programs or systems as the Early Prevention Screening and Diagnostic Treatment Program, special education classes, a range of mental health programs, and programs for specific sub-populations, such as adolescents with chemical dependency and eating disorders. The services that should be offered at each transition stage are described. (Contains 11 references.) (CR)