For-profit schools--also known as proprietary schools--received over $16 billion in federal loans, grants, and campus-based aid under Title IV of the Higher Education Act in 2007/08. The US Government Accountability Office (GAO) was asked to determine (1) how the student loan default profile of proprietary schools compares with that of other types of schools and (2) the extent to which Department of Education's (Education) policies and procedures for monitoring student eligibility requirements for federal aid at proprietary schools protect students and the investment of Title IV funds. To address these objectives, GAO analyzed data and records from Education, examined Education's policies and procedures, reviewed relevant research studies, conducted site visits and undercover investigations at proprietary schools, and interviewed officials from Education, higher education associations, and state oversight agencies. GAO is making three recommendations for Education to strengthen its monitoring and oversight of federal aid eligibility requirements. Specifically, GAO recommends Education (1) improve its monitoring of basic skills tests and target schools for further review; (2) revise regulations to strengthen controls over basic skills tests; and (3) provide information and guidance on valid high school diplomas for use in gaining access to federal student aid. The Department of Education noted the steps it would take to address GAO's recommendations. Three appendices are included: (1) Objectives, Scope, and Methodology; (2) Comments from the Department of Education; and (3) GAO Contact and Staff Acknowledgments. (Contains 2 tables, 8 figures, and 29 footnotes.)