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 Maine'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 Maine's system is compared with other states. Maine's proficiency cut scores generally ranked above average, or relatively difficult, compared with the standards set by the other states in the study. Additionally Maine's minimum subgroup size is 20, which is quite small compared to most other states, resulting in more subgroups being held accountable in Maine than in other states. Students with disabilities had a particularly hard time meeting AYP targets at the middle school level. Compared to the other 27 states examined, Maine places in the middle of the distribution in terms of the number of schools making AYP. The report concludes that although in some respects, Maine'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 8 footnotes, 4 figures, and 5 tables.) [For "The Accountability Illusion," see ED504712. For individual state reports, see ED504680-ED504694, ED504700-ED504711 and ED504719.]