PURPOSE: This workshop will compare and contrast the responsibilities, audiences, methods, data sources, and values used by actuaries and health economists to predict health care costs. For example, actuarial approaches are often used to understand the financial risk of new treatments or payment incentives. In contrast, health economic techniques are used to predict long-term costs and inform outcomes-based arrangements. Both disciplines provide evidence for decision makers on how to manage financial risk and uncertainty while maximizing patient outcomes. DESCRIPTION: For decades, economists and actuaries independently predicted health care costs using different methodologies, assumptions, and values. The actuarial field has focused on the short-term implications of such therapies, with an emphasis on health insurance rate setting. In contrast, the health economics field has focused on treatment value, using metrics such as cost per quality-adjusted life years and cost effectiveness to assess the value of new therapies. However, the current debate on health care value is bringing the two disciplines together. This workshop will use a case study describing the costs and benefits of rheumatoid arthritis treatments to identify similarities and differences between health economic and actuarial disciplines. Gabriela Dieguez and Darius Lakdawalla will present actuarial and health economic analyses for new rheumatoid arthritis treatments. The discussion will contrast the responsibilities, audiences, methods, data sources, and values between disciplines. Karl Gregor will describe the role of each approach to inform health plan decisions and contrast key learnings across both. Jennifer Graff will moderate the panel and audience discussion to identify opportunities for collaboration and improved communication across these disciplines. This interactive workshop will be valuable to health economists, drug developers, and others who develop evidence to inform investment in and reimbursement of technologies. Common understanding of both health economics and actuarial approaches can provide broader insight into value in an era of health reform.