This report uses data from the National Longitudinal Transition Study (NLTS) of Special Education Students to identify specific influences on postschool outcomes of youth with disabilities. The first chapter describes the NLTS, summarizes key postschool outcomes for young people with disabilities, and presents a framework suggesting influential factors. The second chapter considers measurement and analysis aspects of the study, including NLTS data sources and the multivariate modeling approach and statistical techniques used. The third chapter addresses nonschool factors in postschool outcomes including disability-related factors, individual traits, and household characteristics. In the fourth chapter, school factors are examined in relationship to postschool outcomes. Among these factors are the amount of instructional time spent in regular education settings, curricular aspects of academic and vocational programming, and transition planning. The fifth chapter discusses three aspects of student outcomes--academic performance, student behavior at school, and social involvement--as related to postschool outcomes. The sixth chapter considers the direct effects of the amount of time since leaving school. The final chapter summarizes key findings, considers the cumulative effects of various factors in postschool outcomes, and looks at particular groups and the pattern of influences experienced by them. An appendix provides supplemental statistical tables. References are included for each chapter. (DB)