Although state and federal governments heavily subsidize the price of college, estimates of the impact of these subsidies on college enrollment have not been well-identified. I use a regression discontinuity design to study the impact of the CalGrant program in California on college going. Eligibility requires students to meet minimum thresholds on three characteristics: income, assets and high school Grade Point Average. Because there are several dimensions of eligibility, the analysis allows for specification tests, estimating any discontinuities along a given dimension of eligibility, dependent upon whether one satisfied the other two dimensions of eligibility. The paper uses a novel data collection strategy to measure subsequent college enrollment for 150,000 financial aid applicants in 1998 and 1999. The results suggest large impacts (3 to 4 percentage points) of grant eligibility on college enrollment among financial aid applicants, with larger impacts on the choice of private four-year colleges in California.