This paper measures the effects of undergraduate student loan debt on graduates' post-college outcomes: employment, additional enrollment, family formation, home ownership, and net worth. The analysis uses data from a nationally representative sample of 2007-08 bachelor's degree recipients. Because a graduate's debt burden is not randomly assigned, we use an instrumental variable -- enrollment-weighted average in-state tuition over four years -- to estimate the effect of debt on post-baccalaureate outcomes while minimizing selection bias. We find that four years after graduating, undergraduate debt is related to borrowers' earnings, job choice, decisions to marry and have children, and net worth.