The District of Columbia (DC) Opportunity Scholarship Program (OSP) is the only federally funded private school voucher program in the United States. Created in 2004, the OSP aims to provide low-income families with access to higher quality schools than those otherwise available to them. Congress' 2011 reauthorization of the OSP required an independent evaluation of its effectiveness. The study included almost 1,800 student applicants who entered lotteries from 2012 to 2014 and compared the achievement and other outcomes of those who were and were not offered scholarships. The use of random lotteries to award scholarships means that both groups of students were very similar when they applied and later differences reflect only the effects of the OSP. This report presents final findings, three years after students applied. [For the full report, see ED594875. For the technical appendices, see ED594881.]