This proposed exploratory study represents the largest and first investigation in the USA that will purposefully analyse and track students who have sought disability services over a 10-year span (academic years 2000-2011). Using "ex post-facto" data on a non-probability purposive sample of approximately 6000 undergraduates, the research team will address the following research questions: (1) What are the individual characteristics of students registered with the Office for Disability Services (ODS) at Penn State University?; (2) What predictors account for variation in disability service usage among undergraduates from a large state post-secondary educational institution?; and (3) What combination of fixed and malleable variables best predict student performance, persistence and graduation among students with disabilities at a large state post-secondary educational institution? This exploratory study is needed to understand systemic, programmatic and individual barriers that students with disabilities encounter as they transition to and throughout college. Key outcomes from this study will provide a framework for future research to determine the efficacy of existing infrastructure, service practices and institutional policies for college students with disabilities.