Until World War II (1939-1945), most money for medical research in the United States was donated by wealthy individuals, industry, and universities. Scientists resisted government funding because they feared losing the intellectual freedom to study as they chose. Since the 1940s, however, the Federal Government has taken a major role in funding biomedical research.

The National Institutes of Health (NIH) in Bethesda, Maryland, is the biggest government source of research funds. NIH is an agency within the U. S. Department of Health and Human Services. In 2001, the NIH planned to spend about $20.3 billion on biomedical research, distributed to scientists in colleges and universities to conduct specific research projects.

The pharmaceutical industry spent about $26 billion on research in 2000. The next largest source of funds is the Howard Hughes Medical Institute (HHMI), which spends about $554 million annually. Other major funding sources are private foundations and voluntary health organizations. Private foundations are organizations established by wealthy individuals. Among those active in biomedical research are the Charles A. Dana Foundation, the Lucille P. Markey Foundation, and the Whittaker Foundation. Voluntary health organizations are charities supported by contributions from members and the public. Major voluntary health organizations include the American Cancer Society, the American Heart Association, and the American Diabetes Association.