This category includes lists of persons, places, organizations, government agencies, health facilities, laboratories and research institutes, corporations, products, services, and educational programs.

Directories are useful as current reference tools and may also be of historical interest, especially those that provide information regarding an organization's history and influence on biomedicine and public health, include biographical information and photographs, contain details about the structure and governance of significant institutions, or capture trends in health services, education, marketing, or manufacturing. Chronological runs of directories are especially important for historical research.

Collecting emphasis is on U.S. national, U.S. state, international and foreign national directories of physicians and hospitals, and on U.S. national and international directories of other health professionals, health associations, research facilities, corporations, products, services, and programs.

A primary selection criterion is the inclusion of details beyond contact information. Membership rosters without biographical information generally are not collected.