The present study examined the effects of the Class-Wide Function-Related Intervention Team (CW-FIT) program, a group contingency intervention addressing the on-task and disruptive behavior of students with or at risk for emotional behavior disorders (EBD). Twenty-one elementary schools, 155 general education teachers, and 324 students participated in the multisite efficacy trial of CW-FIT over 6 months. Procedures included teaching attending skills, setting goals and awarding points for appropriate behavior, and differential reinforcement and rewards. Students not responding to the primary-level intervention received self-management or help cards as Tier 2 supports. Fidelity of intervention implementation was high across 4 years, with fidelity checks across groups and during baseline conditions. The primary outcome variables of engagement, disruptive behavior, and teacher praise and reprimands were assessed with repeated direct observation. Results confirmed that CW-FIT can be used to increase on-task behavior and reduce disruptive behavior of students with or at risk for EBD.