The institute is centered at the Forest Glen Annex, in the Forest Glen Park part of the unincorporated Silver Spring urban area in Maryland just north of Washington, DC, but it is a subordinate unit of the U.S. Army Medical Research and Development Command (USAMRDC), headquartered at nearby Fort Detrick, Maryland.

The Institute takes its name from Major Walter Reed, MD (1851–1902), the Army physician who, in 1901, led the team that confirmed the theory that yellow fever is transmitted by a particular mosquito species, rather than by direct contact.

Basic and applied medical research supporting U.S. military operations is the focus of WRAIR leaders and scientists.

Despite the focus on the military, however, the institute has historically also addressed and solved a variety of non-military medical problems prevalent in the United States and the wider world.

[2] The PBF at the Forest Glen Annex is a multi-use facility designed and operated for production of vaccines in compliance with the current Good Manufacturing (cGMP) regulations.