"The National Institutes of Health (NIH) is the primary federal agency charged with conducting and supporting biomedical and behavioral research. It is the largest of the eight health-related agencies that make up the Public Health Service (PHS) within the Department of Health and Human Services (HHS). NIH's organization consists of the Office of the Director (OD) and 27 Institutes and Centers. The OD sets overall policy for NIH and coordinates the programs and activities of all NIH components, particularly in areas of research that involve multiple institutes. NIH activities cover a wide range of basic, clinical, and translational research, focused on particular diseases, areas of human health and development, or more fundamental aspects of biomedical research. Its mission also includes research training and health information collection and dissemination. More than 80% of the NIH budget funds extramural research through grants, contracts, and other awards. This funding supports research performed by more than 300,000 individuals who work at over 2,500 hospitals, medical schools, universities, and other research institutions around the country. About 10% of the agency's budget supports intramural clinical and basic research conducted by nearly 6,000 NIH physicians and scientists, most of whom are located on the NIH campus in Bethesda, MD."
CRS Report for Congress, R43341