Tracking students into classes according to academic capability is a common practice in American schools. While tracking can start as early as kindergarten and first grade, the consequences and disadvantages associated with this practice really begin to take root and emerge in middle school and during the transition to high school. Unfortunately, this tracking creates highly stratified learning environments that often limit academic mobility, influence academic trajectories, and privilege certain students while disadvantaging others. To better understand the dynamics that shape, maintain, and situate academic tracking, it is useful to analyse the well-documented outcomes associated with tracking as well as the types of criteria used to sort students into different curricular levels. While there is certainly a great deal of diversity among middle and high schools within the United States, it is safe to assume that academic tracking, in some form or another, is present in an overwhelming majority of them.