Out-of-school suspensions (hereafter referred to as suspensions) are used frequently and for many purposes throughout schools in the United States (Losen & Skiba, 2010; Skiba et al., 2014). A common assumption is that students who receive a suspension will be less likely to engage in problem behavior in the future. Although those who utilize this "get-tough" approach to student misbehavior may assume that exclusionary discipline serves as a deterrent to future problem behavior, research has not supported this theory. This evaluation brief examines the use of suspensions in 1,840 public middle schools in the United States and assesses the extent to which they are effective at reducing future problem behavior for students who receive them. The question of whether, and to what extent, a suspension serves as a deterrent for future exclusionary discipline incidents was evaluated for those students who received one or more suspensions at the beginning of the school year (August, September, or October). To address problem behavior effectively while reducing the rates of exclusionary discipline, it is critical for schools to develop a responsive disciplinary system based on a continuum of responses to student misbehavior. Preventive practices help establish an environment where students are more likely to display appropriate, positive behavior, and less likely to engage in problem behavior. When students do exhibit problem behavior, using instructional responses that are directed at teaching key social skills and re-integrating students into the academic setting, rather than removing them from it, can promote change in student behavior while reducing both the need for and the use of suspensions.