The IOM Roundtable on Evidence-Based Medicine brings together key stakeholders from multiple sectors—patients, health providers, payers, employers, manufacturers, policy makers, and researchers—for cooperative consideration of the ways that evidence can be better developed and applied to drive improvements in the effectiveness and efficiency of medical care in the United States. Evidence-based medicine describes a diverse array of health care initiatives that seek to ensure that medical care received by patients is grounded in the best scientific knowledge and is appropriate for a given individual. Central to the ability to deliver safe, effective, and patient-centered care is a need for better and timelier evidence on which to base clinical decisions about which medical interventions are best, for whom, and under what circumstances.  The health of Americans has greatly benefited from the rapid growth of medical research and technology development. However, multiple studies have shown that far too few of medical services for which there is solid evidence are actually delivered, far too much of our health care spending is devoted to activities that do not improve health, and far too little investment is devoted to better understanding the relative advantages among various intervention choices. This gap in knowledge about what approaches deliver the best results will only be compounded as the pace of technology development quickens and we move into the genomic era of medicine.  These are issues important to the IOM Roundtable on Evidence-Based Medicine, as its members focus on 3 dimensions of the challenge: 1) accelerating progress toward the long-term vision of a learning healthcare system, in which evidence is applied and developed as a natural product of patient care; 2) advancing the near-term capacity to generate the evidence for the medical care that is most effective and produces the greatest value; and 3) improving public understanding about the nature of evidence, its dynamic character and its importance. Roundtables are a specific type of convening activity of The National Academies intended to enable dialogue and discussion among key leaders and representatives in a particular field.  Roundtables are prohibited by the National Academies from producing reports that provide advice or recommendations.