This study evaluated the implementation of the school-based Prevent-Teach-Reinforce (PTR) model within multi-tiered systems of support (MTSS) for elementary school students engaging in high levels of problem behavior. Three students and their classroom teachers in two public schools participated in the team-based PTR process during which they engaged in teaming and goal setting, functional behavior assessment, intervention, and evaluation. A multiple baseline across participants design was used to evaluate the impact of using the PTR model on student problem and replacement behaviors. Direct and indirect observations of student behaviors were conducted across target and generalization academic time periods. Findings indicate that the PTR intervention effectively reduced problem behavior and increased replacement behavior for all three participating students in both target and generalization academic time periods. Social validity assessments with the participating teachers and students indicated high levels of acceptability of and satisfaction with the PTR intervention goals, procedures, and outcomes. Implications for using the PTR model within MTSS for students who are not responding to Tier 2 interventions are discussed. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]