This article illustrates how to (a) use schoolwide data to monitor student responsiveness to primary and secondary prevention efforts to identify students for tertiary preventions and (b) design, implement, and evaluate a function-based intervention in collaboration with two general education teachers, who served as the primary interventionists. Results demonstrate the feasibility and effectiveness of function-based interventions with students who are nonresponsive to primary and secondary prevention efforts. A clear functional relationship was demonstrated between the introduction of the intervention and changes in student behavior using a changing criterion design at the elementary level and an ABAB withdrawal design at the middle school level. Limitations and directions for future research are offered.