These categories are based on definitions adopted by the U.S. Department of Health and Human Services Office of Rural Health Policy (ORHP/HHS). Counties are first classified as either rural or urban depending on the MSA in which they are located.

Rural: Facilities located in non-metropolitan counties, as designated by the MSA method, shall be considered rural. However, portions of urban metropolitan counties may be classified as rural if their census block or tract number is identified by "Goldsmith Modification" methodology. The "Goldsmith Modification" identified rural "pocket" areas within larger urban metropolitan counties.

Urban: Facilities located in metropolitan counties, as measured by the U.S. Office of Management and Budget's MSA method, shall be designated as urban, except for those schools and libraries located within metropolitan counties identified by census block or tract in the "Goldsmith Modification."