The authors examined whether children receiving special education services displayed (a) greater reading or mathematics skills, (b) more frequent learning-related behaviors, or (c) less frequent externalizing or internalizing problem behaviors than closely matched peers not receiving such services. To do so, they used propensity score matching techniques to analyze data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998—99, a large-scale, nationally representative sample of U.S. schoolchildren.