Although health care spending per capita in the United States is more than double that of other industrialized nations, the United States ranks comparatively low on key indicators of the quality of care and population health status. Inefficiencies such as duplicate tests and widespread regional practice variations plague the system. Performance measurement is essential to system transformation. To provide guidance to key stakeholder groups in accelerating toward a high-performing, high-value healthcare system, the National Quality Forum (NQF) convened a Steering Committee to develop a framework for evaluating the efficiency of care over time, including clear definitions and a shared vision of what can be achieved around quality, cost, and value, serving as a foundation for the work of larger performance improvement efforts. This report presents the NQF-endorsed® measurement framework for assessing efficiency, and ultimately value, associated with the care over the course of an episode of illness and sets forth a vision to guide ongoing and future efforts.