This report presents the findings of the cost-benefit analysis of Accelerating Opportunity, an initiative designed to help adults with low basic skills earn industry-recognized credentials in high-growth occupations and succeed in the labor market. It compares the value of the benefits associated with AO--principally labor market benefits--with the costs of the initiative for each of the four participating states: Illinois, Kansas, Kentucky, and Louisiana. In AO's first three years, students in Illinois, Kansas, and Louisiana experienced a net benefit to participating in AO, but only Kansas saw a net social benefit. [For the reports from the first three years of Accelerating Opportunity, see ED559305, ED559322, and ED618150.]