Assessing the evidence for value-based insurance design.

High copayments for medical services can cause patients to underuse essential therapies. Value-based health insurance design attempts to address this problem by explicitly linking cost sharing and value. Copayments are set at low levels for high-value services. The Mercer National Survey of Employer-Sponsored Health Plans demonstrates that value-based insurance design use is increasing and that 81 percent of large employers plan to offer it in the near future. Despite this increase, few studies have adequately evaluated its ability to improve quality and reduce health spending. Maximizing the benefits of value-based insurance design will require mechanisms to target appropriate copayment reductions, offset short-run cost outlays, and expand its use to other health services.