The National Institutes of Health (NIH) is the leading medical research agency in the United States and the largest global source of funding for medical research. Operating under the U.S. Department of Health and Human Services, NIH aims to enhance health by preventing, detecting, diagnosing, and treating a wide range of diseases and disabilities.

NIH comprises 27 Institutes and Centers, each dedicated to specific health areas, and invests approximately $47 billion annually in biomedical and behavioral research. The agency conducts its own research while also providing funding and support to researchers at universities, medical schools, and hospitals worldwide. NIH plays a vital role in training research investigators and disseminating health information to various stakeholders, including healthcare providers and policymakers. Through its collaborative efforts, NIH advances scientific knowledge and improves healthcare outcomes for the public.