Motivated by the multiple-measures clause of recent federal policy regarding student eligibility for alternate assessments based on modified academic achievement standards (AA-MASs), this study examined how scores or combinations of scores from a diverse set of assessments predicted students' end-of-year proficiency status on statewide achievement tests. Scores from 388 eighth-grade students, both with and without disabilities, from 3 states were compared for the predictive validity of test inferences from a set of brief online screening tests, teachers' ratings of performance, and students' previous year's achievement tests. The research team developed screening tests in reading and mathematics that were found to be internally consistent and added predictive value to the identification of students who would perform at a level below proficient on state achievement tests of reading and mathematics. Although achievement results from the previous year were more predictive of future achievement results, scores from the online screening tests and from Performance Screening Guides could be used as supplements to typical achievement tests. Implications of these findings for educators in the 17 states currently using AA-MAS tests for students with disabilities are discussed, and needed future research is identified.