This study investigated associations between enrollment in preschool special education and school readiness skills for children with mild to moderate delays. Findings indicated that on average, children who received preschool special education services had lower scores in reading and math in kindergarten than similar children who did not receive such service. These results could be due to a range of factors that should be explored further, including the nature of special education services for young children as well as possible differences between the groups of children with and without special education experiences. [This research brief is based on the following study: Sullivan, A. L. & Field, S. (2013) Do preschool special education services make a difference in kindergarten reading and mathematics skills?: A propensity score weighting analysis. "Journal of School Psychology."]