The intent of the No Child Left Behind (NCLB) Act of 2001 is to hold schools accountable for ensuring that all their students achieve mastery in reading and math, with a particular focus on groups that have traditionally been left behind. Under NCLB, states submit accountability plans to the U.S. Department of Education detailing the rules and policies to be used in tracking the adequate yearly progress (AYP) of schools toward these goals. This report examines South Carolina's NCLB accountability system, particularly how its various rules, criteria and practices result in schools either making AYP, or not making AYP. It also gauges how tough South Carolina's system is compared with other states. South Carolina's cut scores are relatively difficult to achieve compared to other states in the study: most are above the 50th percentile and some are around the 70th percentile. However, South Carolina adds the equivalent of one standard error to individual test scores, essentially lowers the difficulty of the proficiency cut score. South Carolina also utilizes different subgroup sizes for different groups. A higher-than-most minimum group size for students with limited English proficiency (LEP) means that fewer students are held separately accountable for performance in South Carolina than in similar schools in other states. Compared to the other 27 states examined, South Carolina places in the low end of the distribution in terms of the number of schools making AYP. The report concludes that although in some respects, South Carolina's NCLB accountability system is working as intended by the legislation, NCLB shortcomings are also evident, and should be considerations for Congress in future reauthorizations of the act. (Contains 10 footnotes, 6 figures, and 6 tables.) [For "The Accountability Illusion," see ED504712. For individual state reports, see ED504680-ED504694, ED504700-ED504711 and ED504719.]