The Adolescent Transitions Program (ATP) is a multilevel approach to family-based interventions within a middle-school setting. The intervention strategy is based on an ecological framework for studying social and emotional development in children and adolescents, emphasizing a network of contextual factors within which parenting is both directly and indirectly influential on the development of problem behavior. The ATP model includes a universal, selected, and indicated strategy for serving families with young adolescents. The model is designed to address the needs of families of young adolescents that present with a range of problem behavior and diverse developmental histories. The three interventions levels are described, and outcome data are presented, that support the effectiveness of the ATP model. This approach and the associated data are consistent with a broad literature supporting the effectiveness of family interventions, especially for high-risk youth. The effective implementation of family interventions within a school context suggests that these interventions can make a significant contribution to reducing problem behavior and substance use from a public health perspective.