The most prominent — and certainly the most controversial — feature of the Patient Protection and Affordable Care Act (the ACA, or the Act) is the so-called “individual mandate,” which attempts to address the problem of 50 million uninsured by requiring nearly all Americans, beginning in 2014, to obtain health insurance. While expanded access to health insurance has been both the cornerstone and the lightening rod of the ACA, the Act also contains significant public health provisions focusing on, among other things, promoting the availability of prevention and wellness services. Although these public health provisions have been greeted with mixed reviews, there has been very little discussion of what may be the ACA’s most significant public health feature: the preventive services mandate. In a bold stroke, the ACA changes the way evidence-based preventive services will be provided and paid for by private health insurance plans, Medicare, and Medicaid. By requiring these health plans to provide evidence-based preventive services with no out-of-pocket costs, the ACA transforms the U.S.’s public and private health care financing systems into vehicles for promoting public health.