The purpose of this study was to establish construct validity of a college and career readiness measure using a sample of youth with (n = 356) and without (n = 1,599) disabilities from five high schools across three U.S. states. We established content validity through expert item review, structural validity through initial field-testing, and convergent validity by correlating domain scores with school academic and behavioral data. A four-factor measurement model emerged representing the domains Ownership of Learning, Academic Engagement and Processes, Interpersonal Engagement, and Career Development. Domain scores were significantly correlated with achievement, college admission exam scores, and attendance. Implications for research and practice with an emphasis on transition service delivery via multi-tiered systems of support are discussed.