The United States Department of Agriculture’s Economic Research Service (USDA ERS) recently released the updated Rural-Urban Continuum Codes (RUUCs) for U.S. counties and county equivalents across states and territories. Originally developed in the 1970s, the RUCCs are updated each decade following the Decennial Census. These codes are widely used for conducting research, planning programs, and informing policy.
Starting with metropolitan and nonmetropolitan designations through the U.S. Office of Management and Budget, the RUCCs provide additional subcategories, resulting in nine classifications.
1 = Metro - Counties in metro areas of 1 million population or more
2 = Metro - Counties in metro areas of 250,000 to 1 million population
3 = Metro - Counties in metro areas of fewer than 250,000 population
4 = Nonmetro - Urban population of 20,000 or more, adjacent to a metro area
5 = Nonmetro - Urban population of 20,000 or more, not adjacent to a metro area
6 = Nonmetro - Urban population of 5,000 to 20,000, adjacent to a metro area
7 = Nonmetro - Urban population of 5,000 to 20,000, not adjacent to a metro area
8 = Nonmetro - Urban population of fewer than 5,000, adjacent to a metro area
9 = Nonmetro - Urban population of fewer than 5,000, not adjacent to a metro area
For comparisons between the 2023 and 2013 versions of the RUCCs, it is important to note changes that were implemented to what is considered an urban area by the Census Bureau for 2020 data. The minimum threshold was changed from 2,500 to 5,000 persons.
To learn more about the RUCCs, view a map, and access the data (available in an Excel file), visit