Recently, many states have implemented requirements for scientific or medical accuracy in sexuality education and HIV prevention programs. Although seemingly uncontroversial, these requirements respond to the increasing injection of ideology into sexuality education, as represented by abstinence-only programs. I describe the process by which health professionals and government advisory groups within the United States reach scientific consensus and review the legal requirements and definitions for medical accuracy. Key elements of this scientific process include the weight of scientific evidence, the importance of scientific theory, peer review, and recognition by mainstream scientific and health organizations. I propose a concise definition of medical accuracy that may be useful to policymakers, health educators, and other health practitioners.