This report documents what has been learned through the National Longitudinal Transition Study (NLTS) of Special Education Students about regular education and secondary students with disabilities. Findings are based on data from more than 8,000 youth in secondary special education, ages 13 to 21, in 1985-86. Focus of the report is on how much time students spent in regular education and the effects of regular education on outcomes independent of student and other characteristics. After an introductory chapter, chapter 2 presents a general description of the methodology of the NLTS and a discussion of analytic considerations unique to this report. Chapter 3 looks at characteristics of students with disabilities in regular education. Chapter 4 describes academic and social outcomes during high school associated with time in regular education. Outcomes for young adults in the areas of postsecondary education, employment, independent living, and community participation are presented in chapter 5. Chapter 6 synthesizes findings from the NLTS about regular education and secondary school students with disabilities. (Contains 41 references.) (DB)