This paper applies value-added analysis to study the cognitive development of disabled high school sophomores over the period 1980-1982, in order to determine whether staying in school yields any cognitive return for students with disabilities and to identify those school factors that influence the relationship between staying in school and cognitive return. The study used data about 1,144 students from the data tape for the third follow-up of the "High School and Beyond" sophomore cohort. Student variables included graduation status, student background characteristics, and student achievement; school variables were categorized as demographics, teachers and instructional quality, discipline climate, academic climate, and curricular structure. Results indicated that staying in school yielded considerable cognitive return for students with disabilities, with greater gains in the language development areas and smaller gains in science and math. Tentative results also identified the following factors as moderating the effect of schooling: school type and/or school socioeconomic status, quality of academic instruction, reports of disciplinary problems, percentage of students in academic programs, average number of hours spent on homework, parent interest, and participation in vocational education. Appendices define study variables and provide statistical data. (Contains 13 references.) (JDD)