Researchers have documented the positive effects of classwide peer tutoring on academic performance, engagement, and other social behaviors of students with and without disabilities. Commonly, in classwide peer tutoring, students are paired and the class is divided in half. Points are awarded for tutoring behavior and academic responding during the tutoring session. At the end of the session, the half of the class with the most points earns a reward. In the current study, a fifth-grade teacher implemented classwide peer tutoring for multiplication facts. Instead of the traditional reinforcement system, a randomized classwide interdependent group contingency was implemented. Applying a multiple-probe design across problem sets, students demonstrated increased multiplication fact fluency across three problem sets. Discussion focuses on applied implications for contingency management when implementing classwide peer tutoring programs.