The No Child Left Behind (NCLB) Act of 2001 is the most current iteration of the Elementary and Secondary Education Act of 1965 (ESEA). The stated purpose in 1965 was: “improve the academic achievement of the disadvantaged”.  This underlying principle continues in NCLB, which is currently being discussed by Congress for re-authorization.

NCLB required all states to set up programs that account for student achievement. The law requires students to make Adequate Yearly Progress (AYP) each year, as determined by scores on each state's standardized tests. In Colorado, the Colorado Department of Education uses the Colorado Standardized Assessment Program (CSAP) and Transitional Colorado Assessment Program (TCAP) beginning in 2012 to determine if schools make AYP each year.

In 2012, Colorado applied for and received a waiver from NCLB. The waiver gives Colorado the authority to use the state's accountability system in place of key federal accountability requirements. Colorado's state accountability system will now meet many of the No Child Left Behind requirements, including the requisite to annually determine school and district progress in meeting performance targets.