Under the Affordable Care Act, preventive care measures, including vaccinations and screenings, recommended by the Advisory Committee on Immunization Practices and the US Preventive Services Task Force must be covered in full by insurance. These recommendations affect the cost of medical care. Yet neither organization explicitly incorporates measures of efficiency or cost-effectiveness in making its recommendations. To redress this shortcoming, we propose a decision-making framework for these two organizations based on the principles of economic efficiency. Our analysis suggests that routine use of a preventive service should be recommended for full insurance coverage if the service’s cost-effectiveness exceeds a socially determined threshold. For less cost-effective services, we suggest that information about effectiveness and cost should be provided to consumers by physicians or government, but the choice of care and insurance coverage for care should be made by individuals. For the least cost-effective services, the two organizations should discourage public and private insurers from covering such services and report their unfavorable cost-effectiveness.