• 2010 Urban Area to County Relationship File Layout (ua_county_rel_10.txt)
• 2010 Urban Area to County Subdivision Relationship File Layout (ua_cousub_rel_10.txt)
• 2010 Urban Area to Place Relationship File Layout (ua_place_rel_10.txt)
• 2010 Urban Area to Metropolitan and Micropolitan Statistical Area (CBSA) Relationship File Layout (ua_cbsa_rel_10.txt)
• 2010 Urban Area to New England City and Town Area (NECTA) Relationship File Layout (ua_necta_rel_10.txt)
• 2010 Urban Area to ZIP Code Tabulation Area (ZCTA) Relationship File Layout (ua_zcta_rel_10.txt)

This relationship file contains the population, housing unit count, total area, and land area for each unique urban area-county combination; the population, housing unit count, total area, and land area of the entire participating urban area and county entities; and the percent population, housing unit count, total area, and land area that each combination represents of the entire participating urban area and county entities.

For records corresponding to parts of or entire county entities that do not overlap any 2010 urban area, the urban area code is 99999, the urban area name is “Not in a 2010 urban area”, and the urban area population, housing unit count, total area, and land area values are null. The percent values relating to the urban area are also null.

Area measurements are in square meters.

This relationship file contains the population, housing unit count, total area, and land area for each unique urban area-county subdivision combination; the population, housing unit count, total area, and land area of the entire participating urban area and county subdivision entities; and the percent population, housing unit count, total area, and land area that each combination represents of the entire participating urban area and county subdivision entities.

For records corresponding to parts of or entire county subdivision entities that do not overlap any 2010 urban area, the urban area code is 99999, the urban area name is “Not in a 2010 urban area”, and the urban area population, housing unit count, total area, and land area values are null. The percent values relating to the urban area are also null.

Area measurements are in square meters.

Note that only urban areas and county subdivisons that occur in states with governmental county subdivisions (minor civil divisions) are included in this file: Connecticut, Illinois, Indiana, Kansas, Maine, Massachusetts, Michigan, Minnesota, Missouri, Nebraska, New Hampshire, New Jersey, New York, North Dakota, Ohio, Pennsylvania, Rhode Island, South Dakota, Vermont, and Wisconsin.

This relationship file contains population, housing unit count, total area, and land area for each unique urban area-place combination; population, housing unit count, total area, and land area of the entire participating urban area and place entities; and percent population, housing unit count, total area, and land area that each combination represents of the entire participating urban area and place entities.

For records corresponding to parts of or entire place entities that do not overlap any 2010 urban area, the urban area code is 99999, the urban area name is “Not in a 2010 urban area”, and the urban area population, housing unit count, total area, and land area values are null. The percent values relating to the urban area are also null.

For records corresponding to parts of or entire urban area entities that do not overlap any 2010 place, the place code is 99999, the place name is “Not in a census designated place or incorporated place”, the GEOID values is <ST>99999 (where <ST> is the state FIPS code), and the class code, place population, housing unit count, total area, and land area values are null. The percent values relating to the place are also null.

Area measurements are in square meters.

Note that the term “place” here refers collectively to incorporated places and census designated places.

This relationship file contains the population, housing unit count, total area, and land area for each unique urban area-metropolitan and micropolitan statistical area (CBSA)  combination; the population, housing unit count, total area, and land area of the entire participating urban area and CBSA entities; and the percent population, housing unit count, total area, and land area that each combination represents of the entire participating urban area and CBSA entities.

For records corresponding to parts of CBSA entities that do not overlap any 2010 urban area, the urban area code is 99999, the urban area name is “Not in a 2010 urban area”, and the urban area population, housing unit count, total area, and land area values are null. The percent values relating to the urban area are also null.

For records corresponding to parts of or entire urban area entities that do not overlap any 2010 CBSA, the CBSA code is 99999, the CBSA name is “Not in a metro/micro area”, and the CBSA population, housing unit count, total area, and land area values are null. The percent values relating to the CBSA are also null.

Area measurements are in square meters.

These metropolitan and micropolitan statistical areas, current on April 1, 2010 (Census Day), were created in 2009. New metropolitan and micropolitan statistical areas defined using the results of the 2010 Census are scheduled for release in 2013.

This relationship file contains the population, housing unit count, total area, and land area for each unique urban area-New England city and town metropolitan and micropolitan statistical area (NECTA) combination; the population, housing unit count, total area, and land area of the entire participating urban area and NECTA entities; and the percent population, housing unit count, total area, and land area that each combination represents of the entire participating urban area and NECTA entities.

For records corresponding to parts of NECTA entities that do not overlap any 2010 urban area, the urban area code is 99999, the urban area name is “Not in a 2010 urban area”, and the urban area population, housing unit count, total area, and land area values are null. The percent values relating to the urban area are also null.

For records corresponding to parts of or entire urban area entities that do not overlap any 2010 NECTA, the NECTA code is 99999, the NECTA name is “Not in a NECTA”, and the NECTA population, housing unit count, total area, and land area values are null. The percent values relating to the NECTA are also null.

Area measurements are in square meters.

Note that only urban areas and NECTAs that occur in the New England states are included in this file: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont.

These NECTAs, current on April 1, 2010 (Census Day), were created in 2009. New NECTAs defined using the results of the 2010 Census are scheduled for release in 2013.

This relationship file contains the population, housing unit count, total area, and land area for each unique urban area-ZIP Code tabulation area (ZCTA) combination; the population, housing unit count, total area, and land area of the entire participating urban area and ZCTA entities; and the percent population, housing unit count, total area, and land area that each combination represents of the entire participating urban area and ZCTA entities.

For records corresponding to parts of or entire ZCTA entities that do not overlap any 2010 urban area, the urban area code is 99999, the urban area name is “Not in a 2010 urban area”, and the urban area population, housing unit count, total area, and land area values are null. The percent values relating to the urban area are also null.

For records corresponding to parts of or entire urban area entities that do not overlap any 2010 ZCTA, the ZCTA5 code is 99999 and the ZCTA population, housing unit count, total area, and land area values are null. The percent values relating to the ZCTA are also null.

Area measurements are in square meters.