Many youth experience mental health problems. Schools are an ideal setting to identify, prevent, and intervene in these problems. The purpose of this study was to investigate patterns of student social, emotional, and behavioral risk over time among a community sample of 3rd through 12th grade students and the association of these risk patterns with fidelity to a school-based mental health model. Overall growth of social, emotional, and behavioral problems declined over a 3-year period. Four classes of students were identified using growth mixture modeling: (1) students with high levels of problems, (2) students with decreasing problems, (3) students with increasing problems, and (4) students with stable, low levels of problems. These growth trajectories were associated with fidelity to the model, in that trajectories where students with higher or increasing problems were more likely to be from schools with lower fidelity. Implications for practice and policy are provided.