This report describes student borrowing by comparing different groups of undergraduate borrowers. Two sets of borrower groups are examined: (1) high, medium, low, and nonborrowers as defined by borrowing from all sources in 1999-2000 (excluding federal Parent Loans for Undergraduate Students and loans from family or friends); and (2) Stafford loan maximum borrowers, less-than-maximum borrowers, and Stafford nonborrowers. The analysis of borrower groups explores demographic and enrollment characteristics, risk for not persisting to completion of an educational program, and types of loans and other financial aid received. The final analysis in the report considers all borrowers as a group and explores the likelihood of borrowers with certain characteristics obtaining particular types of financial aid. Twenty-nine percent of undergraduates borrowed from some source to help finance postsecondary education in 1999-2000. Data from the 1999-2000 National Postsecondary Student Aid Study were used for this report to provide a nationally representative sample of undergraduates enrolled at postsecondary institutions that participated in federal student aid programs. Findings show that high borrowers received an average of $9,680 in loan aid. Ninety-eight of high borrowers received Stafford loans and about one-quarter received private loans. Seventy-one percent of the high borrowers received some form of grant aid as well in 1999-2000. Borrowers who were financially independent who attended private-for-profit institutions and who attended exclusively full time were more likely to have received both federal Stafford subsidized loans and Stafford unsubsidized loans. Appendixes contain a glossary and technical notes. (Contains 18 tables, 5 figures, and 12 references.) (SLD)