As part of No Child Left Behind, parents of low-income students in low-performing schools are offered Supplemental Educational Services (SES) for their children. These academic supports, such as extra tutoring or group sessions, take place outside the regular school day. A report and executive summary for the Institute of Education Sciences examine potential achievement benefits. In the six study districts located in Connecticut, Florida, and Ohio, the program was directed to the lowest-achieving students due to oversubscription. However, not all students who were offered access to the program participated. The study found no evidence of impacts from offering SES to students near the cutoff of acceptance into the program. Furthermore, there were no impacts from participating in SES on student achievement in reading or math. Providers offered an average of 21 hours of SES per student for the school year, either one-on-one or in group sessions conducted by local teachers. No observed provider characteristics and practices, including intensity of services, were significantly associated with stronger impacts. The six districts were not nationally representative.