Expanding the delivery of efficacious public health and prevention strategies holds considerable potential for improving health outcomes and constraining costs across the U.S. health system. Unfortunately, lingering certainties about the costs required to expand public health delivery systems and about the health and economic effects of such expansions has muted private and public support for increased public health expenditures. This lecture examines recent evidence from public health services and systems research studies that examine the health and economic value of public health delivery, and identifies remaining research needs for the field.