This study examined characteristics differentiating defaulters on Stafford student loans (formerly Guaranteed Student Loans) from non-defaulters. Data were drawn from a sample of 100,000 records randomly selected from the fiscal year 1987 guarantee agency cumulative borrower file. A cohort of 7,382 borrowers taking out their last loan in FY 1983 was divided into defaulters and non-defaulters. The relationships of five variables (institution type, adjusted gross income, dependent/independent status, enrollment status--graduated or withdrew, and years of schooling completed) with each other and with default/non-default status were examined. The study also provides cohort default rates for various borrower subpopulations based on a large, national random sample, furnishes a comprehensive summary and critique of the literature, and suggests potentially fruitful avenues for further research. (MSE)