The federal government delivers substantial college aid through the tax code. The designs of the Lifetime Learning tax credit and the tuition deduction may make them particularly useful to older students. This paper investigates how these provisions affect college attendance of individuals in their 30s and 40s. Using panel data and fixed effects instrumental variable estimation, I find no effect on adult college attendance or degree completion. There is a positive effect on college attendance among a subsample, those whose 1998 educational attainment fell short of earlier expectations. Overall, these results suggest that tax-based aid subsidizes inframarginal college attendance among adults.