The authors present an investigation of a classwide intervention to reduce disruptive behavior in a kindergarten classroom. Participants included children in 3 kindergarten classrooms and their teachers in an at-risk school district in Northeast Ohio. On the basis of student behaviors and teacher goals, the authors chose the Good Behavior Game plus Plus Merit. A total of 3 teachers implemented the Good Behavior Game Plus Merit in the classroom. The authors used a single-subject reversal design (ABAB) to test experimental control. They collected direct observations of student behavior during each phase of the intervention. Results indicated a decrease in negative, disruptive behavior during intervention. Last, the authors discuss the implications for implementing this intervention in the kindergarten classroom. (Contains 1 table and 1 figure.)