In conjunction with the Individuals with Disabilities Education Act of 1997 (IDEA; PL 105-17), the No Child Left Behind Act of 2002 (NCLB; PL 107-110) calls for enhancements to existing assessment and accountability systems within specific timelines. The NCLB Act also stresses the importance of using reliable and valid data for decision making. This study examined the consequential validity of a large-scale alternate assessment system for students with severe cognitive disabilities in one midwestern state. Three hundred and four teachers completed a survey designed to measure their perceptions of the alternate assessment's influence on instruction and the development of individualized education programs (IEPs). Findings indicated the assessment had a strong influence on instruction and a strong, but lesser influence on the development of IEPs. (Contains 3 tables and 3 figures.)