This study examined the rate of participation in, and default on loans from, the Federal Parent Loans for Undergraduate Students (PLUS) and the Federal Supplemental Loans for Students (SLS) programs. In particular the study sought to know the volume of loans made to students or parents of students attending proprietary (trade) schools and other postsecondary educational institutions, the extent of borrowing by parents of freshmen and by freshmen students as compared to such borrowing for students in their second or subsequent years of schooling, and the amount of defaulted loans. The study proceeded by soliciting loan volume data for fiscal years 1989 to 1991 from 11 of the largest guaranty agencies, which together accounted for 63 percent and 62 percent of the PLUS and SLS total loan volumes. Ten of the agencies also provided loan default data. The review found that $1.7 billion in PLUS loans and $3.7 billion in SLS loans were made during the period. In addition most of the PLUS loan volume went to parents of students attending nonproprietary schools and most of the PLUS volume increase was among non-freshmen at nonproprietary schools. New loan defaults increased during each of the 3 years and totaled almost $109 million for PLUS loans and $1.4 billion for SLS loans. Numerous tables and figures supplement the text. (JB)