The purpose of this study was to analyze similarities and differences in how students with disabilities are identified in national databases. National data collection programs in the U.S. Departments of Education, Commerce, Labor, Justice, and Health and Human Services, as well as databases from the National Science Foundation, the American Council of Education, and the College Board, were examined. Nineteen national data collection programs were selected as being potentially useful in the extraction of policy-relevant information on the educational status and performance of students with disabilities. Among these 19 programs there was significant variability in the disability categories used. These programs were targeted for two reasons: (a) their potential usefulness in providing indicators of domains in key models of educational outcomes for children and youth with disabilities, and (b) their prominence in current efforts to monitor progress toward the attainment of national education goals. Discussed are issues related to improving disability identification in large-scale data collection programs and the effects of these issues on reporting policy-relevant information.