Background: From the perspective of schools, children's mental health is essential to academic success. Multitiered systems of support (MTSS) that provide prevention/promotion, early identification/intervention, and clinical treatment services have been embraced as a promising means to deliver mental health services in the school setting. Methods: A school-hospital partnership tested the implementation over 3 consecutive academic years of an MTSS model for elementary through high-school students enrolled in 6 urban public schools. The model was designed to embed whole-school and classroom-level prevention/promotion programs alongside small group and individual services for selected youth. Utilization, satisfaction, and student- and school-level outcomes were assessed. Results: Students participating in early intervention had significantly improved social-emotional competencies and coping skills (particularly those students at highest risk), and students with mental health disorders who participated in clinical treatment had significantly improved symptoms and functioning. Schools significantly enhanced their capacity to provide mental health services across prevention/promotion, early identification/intervention, and crisis management domains. These findings were replicated across 3 consecutive years of program implementation. Conclusions: A school-hospital partnership using an MTSS model was found to be feasible, valued, and effective in improving students' mental health status and schools' capacities to provide mental health services.