Observers from across the ideological spectrum argue that the US is in the midst of a student debt crisis. This report takes an approach to understanding who holds student debt by examining borrowers' characteristics when the loans were originated. To help fill a void in the research, this analysis focuses on borrowing patterns among students who enrolled in an institution of higher education in the 1995-96 and 2015-16 academic years. (It includes data points for the intervening years in an appendix.) The analysis is limited to two main statistics for undergraduates by family income: the share of students who took on debt and the amount they borrowed.