This report, the third of three reports examining Supplemental Education Services (SES) within the Wake County Public School System (WCPSS), focused on the long-term goal of improved student achievement by the end of the school year. In 2009-10, 508 students participated in SES at the five schools offering SES: Brentwood, Fox Road, Poe, Wendell, and York. The vast majority of students (83%) participating in SES received tutoring services in both reading and mathematics. Overall, this study did not support the value of SES in promoting higher achievement (beyond what matched students achieved). The following appendices are included: (1) SES Participants' Reading and Mathematics Achievement 2009-10; and (2) Reading and Mathematics EOG Mean Scale Scores for Matched Students. [For the first report in the series, see ED564353. For the second report in the series, see ED564360.]