A commonly accepted definition of health literacy in the United States is:
"The degree to which an individual has the capacity to obtain, communicate, process, and understand basic health information and services to make appropriate health decisions." [U.S. Department of Health and Human Services. 2000. Healthy People 2010. Washington, DC: U.S. Government Printing Office. Originally developed for Ratzan SC, Parker RM. 2000. Introduction. In National Library of Medicine Current Bibliographies in Medicine: Health Literacy. Selden CR, Zorn M, Ratzan SC, Parker RM, Editors. NLM Pub. No. CBM 2000-1. Bethesda, MD: National Institutes of Health, U.S. Department of Health and Human Services.]
A National Academy of Medicine Discussion Paper called for a broader, multidimensional definition of health literacy to more accurately define the issue and promote research to identify effective knowledge, skills and practices for mitigation: Pleasant, A., R. E. Rudd, C. O’Leary, M. K. Paasche-Orlow, M. P. Allen, W. Alvarado-Little, L. Myers, K. Parson, and S. Rosen. 2016. Considerations for a new definition of health literacy. Discussion Paper, National Academy of Medicine, Washington, DC. This is further discussed in the article The Arc of Health Literacy [Koh, H. K., & Rudd, R. E. (2015). The arc of health literacy. Jama, 314(12), 1225-1226. doi:10.1001/jama.2015.9978].
As of August 2020, an expanded definition is now found in the Healthy People 2030 objectives. Both personal health literacy and organizational health literacy are addressed. These definitions expand the idea of health literacy to people's ability to use rather than only understand the information, as well as recognize the responsibility of organizations in addressing contextual factors of health literacy.
Personal health literacy: the degree to which individuals have the ability to find, understand, and use information and services to inform health-related decisions and actions for themselves and others.
Organizational health literacy: the degree to which organizations equitably enable individuals to find, understand, and use information and services to inform health-related decisions and actions for themselves and others.