Measurement of health care quality and patient safety is rapidly evolving, in response to long-term needs and more recent efforts to reform the US health system around "value." Development and choice of quality measures is now guided by a national quality strategy and priorities, with a public-private partnership, the National Quality Forum, helping determine the most worthwhile measures for evaluating and rewarding quality and safety of patient care. Yet there remain a number of challenges, including diverse purposes for quality measurement, limited availability of true clinical measures leading to frequent reliance on claims data with its flaws in determining quality, fragmentation of measurement systems with redundancy and conflicting conclusions, few high-quality comprehensive measurement systems and registries, and rapid expansion of required measures with hundreds of measures straining resources. The proliferation of quality measures at the clinician, hospital, and insurer level has created challenges and logistical problems. Recommendations include raising the bar for qualtiy measurements to achieve transformational rather than incremental change in the US quality measurement system, promoting a logical set of measures for the various levels of the health system, leaving room for internal organizational improvement, harmonizing the various national and local quality measurement systems, anchoring on National Quality Forum additions and subtractions of measures to be applied, reducing reliance on and retiring claims-based measures as quickly as possible, promoting comprehensive measurement such as through registries with deep understanding of patient risk factors and outcomes, reducing attention to proprietary report cards, prompt but careful transition to measures from electronic health records, and allocation of sufficient resources to accomplish the goals of an efficient, properly focused measurement system.