Over the last century, Americans have experienced unprecedented advances in health care. Average life expectancy has increased by nearly 30 years, and as a nation, we are enjoying healthier and more productive lives. We are moving closer every day in our quest to find new treatments and cures for diseases that affect millions of Americans. Much of this progress is due to the advances that have emerged from our investments in health care research. These investments have led to a strong foundation of scientific evidence that has been accumulated over time from many sources. These include basic science carried out in laboratories, clinical trials underway in hospitals and other health care settings, and health services research that is conducted by investigators in both clinical and nonclinical settings. As a result, the health care we receive today may be the most technologically sophisticated and highest quality care in the world. However, as we move ahead in this new century, it has become apparent that the care known to be effective is not always the care we receive. Indeed, all too often health care causes harm. One recent report concluded that tens of thousands die each year from errors in their care. Indeed, medical errors could be among the top 10 causes of death in the United States. Today, we are experiencing an unprecedented volume and pace of change in the U.S. health care system. These changes are not occurring uniformly across the country, and they affect different population groups in different ways. While medical science and technology continue to provide promising advances, our health care system often struggles to keep up and deliver those advances to patients in the form of improved health care. Recognizing this, the Institute of Medicine recently reported that "between the health care we have and the care we could have lies not just a gap but a chasm." The urgency for addressing the issues underlying this chasm has increased as a result of events that occurred in the aftermath of September 11. We must find ways to respond quickly and efficiently to threats of bioterrorism and other public health emergencies. AHRQ supports and conducts health services research on health care quality, patient safety, access to care, medical effectiveness, the costs of care and how we pay for care, and many other issues that are crucial to the future health and well being of the American people. This report presents information on the programs and activities undertaken by AHRQ in FY 2002. It includes examples of some recent accomplishments and a description of the research priorities that will shape our activities in the months ahead. To set the stage for this discussion, the report describes AHRQ's organizational structure and the key responsibilities of functional components, discusses the role of the agency's National Advisory Council and identifies the various audiences and customers who use and depend on the findings from agency-supported research.