The Census Bureau has the longest-standing definition of rural as open country and settlements of less than 2,500 residents, excluding suburbs of urbanized areas with 50,000 or more population. For the 2000 census, revised tabulating procedures extended the classification of urban-like suburbs to include small towns (“urbanized areas”).2 This transferred a number of people to urban status who had previously been classified as rural, especially in the Northeast. In 2000, the rural population was measured at 59.0 million, or 21 percent of the total population.

OMB expands the Census Bureau’s definition to a county-based approach to measure the extent to which a large city’s (central city) economic influence extends beyond its limits. The level of intercounty job commuting is the principal means of determination. The terms “metropolitan,” “micropolitan,” and “noncore” are used to describe the areas of measurement. A metropolitan area is defined as a county with a central city and its adjoining counties that together have more than 50,000 people, regardless of the size of the largest central city (FR, 2000). Micropolitan areas are defined as counties that have a town of at least 10,000 population; outlying counties are included if commuting to the central county is 25 percent or higher. Noncore counties are those not near an urbanized area of 10,000 or more. Most recently, the 2004 Omnibus Appropriations Bill broadened the definition of rural to include any incorporated city or town of 20,000 persons or less rather than using the OMB definition in order to broaden eligibility for participation in USDA’s Rural Broadband Grant and Loan Program.

The ERS has developed two other types of measurements for population comparisons—the rural–urban continuum codes and the urban influence codes. The rural–urban continuum codes (see Figure B-1) are used to distinguish metropolitan counties by size and nonmetropolitan counties by their degree of urbanization and adjacency to metropolitan areas. Metropolitan areas can measure more than 1 million or less than 250,000, and nonmetropolitan codes range from +20,000, adjacent to a metropolitan area, to completely rural, or <2,500 not adjacent.


Free-standing towns of 2,500 to 9,999 are often considered rural because of their modest scale and relevance to providing health services for a larger surrounding rural area; counting these towns would add another 11.1 million to the rural total. Above this, 7.6 million live in clusters of 10,000 to 19,999 population, and 11.3 million in clusters of 20,000 to 49,999. The population total of all the rural and urban cluster categories is 89 million (FR, 2000).

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