We document that 11 percent of recent U.S. high school graduates did not apply for federal student aid due to difficulty in applying, mistaken beliefs, or lack of awareness. Not applying due to such application frictions negatively predicts college enrollment after controlling for other attributes. We represent application frictions as heterogeneous filing costs in a general equilibrium life cycle model of college enrollment. We find that eliminating these frictions generates modest gains on average because less than half of those affected would ultimately utilize aid. However, welfare gains are large for the affected few with high skill and poor parents.