This study explored the effects of a group-contingency intervention on student behavior across academic instructional periods. Research suggests group contingencies are evidence-based practices, yet calls for investigation to determine the best conditions and groups suited for this type of intervention. CW-FIT (Class-Wide Function-related Intervention Teams), an interdependent-group contingency intervention, was implemented in a first grade general education classroom across three academic periods. Results indicate student on-task behavior and teacher praise increased after intervention in all three settings. In addition, three students identified as at-risk for problem behaviors decreased disruptive behaviors in response to the intervention.