Afterschool programs, the heart of the supplemental service provision of No Child Left Behind (NCLB), take on increasing significance in the implementation of the historic federal law. As more and more schools fail to make their NCLB-mandated Adequate Yearly Progress (AYP) goals, the demand for supplemental education services, such as tutoring, summer school, or, most often, instruction after the end of the regular school day, is skyrocketing. Especially within big cities, where the largest concentrations of disadvantaged students reside, these afterschool programs are becoming one of the most popular features of the Bush administration's school reforms. The supplemental services program has major potential, but it is freighted with an inherent conflict of interest that could prove its undoing: the same school districts that are failing to make AYP are the gatekeepers for these afterschool funds. As the stakes increase, so does the funding, and so do the incentives to control those dollars. The federal focus on failing districts is understandable, given the way the law is currently phrased. But in terms of public policy, the central issue is not whether a district is failing but whether school districts should both offer services and control the terms of access by private providers. Though ignored in most of the public discussion, the financial conflict of interest is clear: school districts are given the authority to monitor afterschool education vendors even while acting as vendors themselves. How this power struggle will evolve, and whether students will benefit, remains the big unknown. Unfortunately, the accountability provisions of NCLB do not contain any mechanism for ensuring that students profit from afterschool programs, mainly because states are focusing more on overall school performance than on the performance of individual students. Only if the NCLB accountability system can be gradually shifted to a student focus will the impact of afterschool programs become a part of planning for the future. (Contains 1 table and 2 figures.)