Adequate yearly progress (AYP) is a federal accountability measure established under the No Child Left Behind Act of 2001 (NCLB). Under the AYP system, states established timelines for improving the academic achievement level of over 12 years, at the end of which 100% of students in all subgroups should perform at the proficient level or better. This entry first discusses the regulations establishing the AYP measure and the reception of the AYP process by administrators, parents, and educators. It then looks at the impact of AYP on student achievement, how the percentage of schools failing to make AYP increased over the years, and the waiver system introduced in 2011.