Half of college students drop out without completing a degree. This paper establishes a causal link between college costs and degree completion. I use quasi-experimental methodology to analyze two state scholarship programs. The programs increase the share of the exposed population with a college degree by three percentage points, with stronger effects among women. A cost-benefit analysis indicates that the programs are socially efficient at rates of return to schooling as low as 5 percent. Even with the offer of free tuition, many students continue to drop out, suggesting tuition costs are not the only impediment to college completion. (Contains 9 tables, 3 figures and 35 footnotes.)