Rural-Urban Commuting Area Codes

The rural-urban commuting area (RUCA) codes classify U.S. census tracts using measures of population density, urbanization, and daily commuting. A second dataset applies 2010 RUCA classifications to ZIP code areas by transferring RUCA values from the census tracts that comprise them. The most recent RUCA codes are based on data from the 2010 decennial census and the 2006-10 American Community Survey. The classification contains two levels. Whole numbers (1-10) delineate metropolitan, micropolitan, small town, and rural commuting areas based on the size and direction of the primary (largest) commuting flows. These 10 codes are further subdivided based on secondary commuting flows, providing flexibility in combining levels to meet varying definitional needs and preferences. Descriptions of the codes are found within the data files, and also in the Documentation.

State and county names included on the file provide initial help in locating census tracts of interest (all census tracts are nested within counties). To determine the census tract for a particular location within a county, please go to https://geomap.ffiec.gov/FFIECGeocMap/GeocodeMap1.aspx. 

Earlier versions of the RUCA codes (1990 and 2000) are also available. All three versions use the same primary classification scheme (1-10) but are not directly comparable because many census tracts are reconfigured during each decade. Also, changes to census methodologies significantly affected the RUCA classifications. Between 1990 and 2000, changes to methods for defining urban areas decreased rural population and territory. Between 2000 and 2010, the data source for daily commuting patterns switched from the decennial census (measuring one point in time during 2000) to the American Community Survey (providing a 5-year average during 2006-10). See data source information within the individual data files for details.

Errata: On July 3, 2019, the Rural-Urban Commuting Area (RUCA) Codes data product was revised to correct a programming error affecting the 2010 secondary RUCA codes. The revision corrects the secondary codes of 10,909 of 74,002 census tracts. Secondary RUCA codes may be used to classify census tracts into rural and urban categories. The revised secondary codes result in an increase in the number of census tracts classified as rural. The 2010 primary RUCA codes were not affected by this revision.

On August 17, 2020, a ZIP code version of the 2010 RUCA codes was added to this data product. It replaces the ZIP RUCA 3.1 dataset maintained by the University of North Dakota’s Center for Rural Health, and reflects the correction to the secondary codes described above.