The school-choice landscape in the United States is undergoing a rapid transformation, as states increasingly enact a new form of vouchers called Education Savings Accounts (ESAs). Unlike earlier voucher programs, which generally allowed subsidies only for private school tuition, ESAs represent a radically expansive--and potentially very costly--vision for the private use of public education funds. ESA participants receive public monies via direct deposit and can use them for various expenses, including private school tuition and fees. Many states, in fact, allow the funds to be used for nearly any purportedly educational expense. ESA funds are thus widely dispersed among participants and private providers with surprisingly little or no oversight or accountability. This policy brief explores the evolution of these ESA programs, with attention to the policy characteristics that shape this large transfer of unrestricted public subsidies for private and at-home education.