ISSUE: Value frameworks have been proposed in the United States (US) to inform decisions regarding the funding of new interventions. None of these has included an explicit and empirical consideration of opportunity cost. The mechanisms by which opportunity costs are realized vary depending on the system, but a decision to fund a specific intervention always has the potential to impose costs on others in terms of forgone benefits. Empirical estimates of opportunity costs have been generated in the UK to inform decisions about the NHS cost-effectiveness threshold, and similar research is underway elsewhere. Is there a need for estimates of opportunity cost in the US? Willke will chair and set up the issues and challenges. Sculpher will outline the rationale for quantifying opportunity costs to guide decisions and describe international research to estimate them. Pearson will consider the role of cost-effectiveness thresholds in value frameworks in the US and whether these can and should reflect opportunity costs. Basu will describe some of the challenges in estimating opportunity costs to guide decisions appropriately. OVERVIEW: Decisions regarding the allocation of resources to alternative interventions are a major challenge in all jurisdictions. Formal cost-effectiveness analysis (CEA) has been used to support these decisions in some countries, but this has been limited in the US. The enduring need for an evidential basis to decisions about price and reimbursement in the US has led to the development of a range of value frameworks. These seek to conceptualize the different benefits offered by new interventions and how these may be traded off. Unless the capacity to benefit from health care has been satisfied for all individuals, the decision to fund one intervention necessarily means others forgoing benefits. The magnitude of these opportunity costs should arguably inform resource allocation decisions but has not been incorporated into any of the value frameworks.