School voucher programs have become a prominent aspect of the education policy landscape in the United States. The DC Opportunity Scholarship Program is the only federally funded voucher program in the United States. Since 2004 it has offered publicly funded private school vouchers to nearly four thousand students to attend any of seventy-three different private schools in Washington, DC. An official experimental evaluation of the program, sponsored by the federal government's Institute of Education Sciences, found that the students who were awarded Opportunity Scholarships graduated from high school at a rate 12 percentage points higher than the students in the randomized control group. This article estimates the benefit/cost ratio of the DC Opportunity Scholarship Program, primarily by considering the increased graduation rate that it induced and the estimated positive economic returns to increased educational attainment. We find a benefit to cost ratio of 2.62, or $2.62 in benefits for every dollar spent on the program.