The **National Institutes of Health (NIH)** is the United States' foremost federal agency dedicated to biomedical and public health research, operating under the Department of Health and Human Services. Established in 1887 initially as the Hygienic Laboratory, it has since evolved into the largest biomedical research funder globally, with an annual budget of approximately $47–48 billion and a workforce of about 18,700 employees[2][4][7]. NIH’s mission is to seek fundamental knowledge about living systems and apply that knowledge to enhance health, extend life, and reduce illness and disability. It achieves this by conducting direct research, funding studies at universities and hospitals nationwide, training scientists, and disseminating medical information[1][2][7]. The agency comprises 27 specialized Institutes and Centers (ICs), each focused on specific diseases or biological systems, such as cancer, heart disease, infectious diseases, aging, and neurological disorders[1][3][8]. Key historical milestones include its formalization as the nation’s primary medical research agency in 1944 under the Public Health Service Act and major expansions during the mid-20th century. One of its landmark achievements was leading the Human Genome Project (1990–2003), which mapped the human DNA sequence and revolutionized genetics and personalized medicine[2][3]. NIH research has contributed to many medical breakthroughs, including vaccines for hepatitis, human papillomavirus (HPV), and bacterial infections, as well as treatments for bipolar disorder and tooth decay prevention[3]. Its intramural research program is the world’s largest biomedical research enterprise, while its extramural funding supports over a quarter of all U.S. biomedical research annually[3]. Located primarily in Bethesda, Maryland, with facilities nationwide, NIH is noted for its scientific rigor, public accountability, and fostering innovation that drives advances in biotechnology, pharmaceuticals, and healthcare. It remains a critical institution at the intersection of science, technology, and public health polic