This study examines the causal effect of a diploma on health using a regression discontinuity approach. During WWII, cohorts of men in the United States whose birthdays fell within particular intervals of time were required to register for the draft on specific dates. These policies created discontinuities in registration age, which subsequently resulted in discontinuities in graduation rates. Because mandatory registration ages fell as the war progressed, the independent variable, diploma receipt, can be measured in terms of both a high school and a college diploma. The results indicate that both forms of credentialing directly improve physical wellness and increase the utilization of health care. These effects are larger than those estimated using ordinary least squares.