The Affordable Care Act (ACA) transforms the U.S.'s public and private health care financing systems into vehicles for promoting public health by making evidence-based preventive services available nationwide through individual and group health plans, Medicare, and Medicaid. The ACA accomplishes this transformation by breaking down two barriers: (1) the public health-health care divide, which led to a dominance of curative medicine over preventive health measures and (2) ERISA preemption, which created an obstacle to the provision of a uniform set of evidence-based preventive services that could be made available to the U.S. population through individual and group health plans. As a result, prevention measures with proven effectiveness will now be provided on a national and uniform basis to a majority of Americans, with the potential to improve health outcomes and reduce costs.