crosswalk_zip_county
ZIP code (ZCTA) to county mapping. One row per ZIP code. For each ZCTA, maps to the county with the largest land-area overlap per the 2020 Census ZCTA-county relationship file. Use to convert ZIP-level data to county grain.
overview
~33,000 ZCTAs mapped to the county with the largest land-area overlap per 2020 Census relationship file.
current vintage — 2020 Census
history — 2010 and 2020 vintages differ; this table reflects 2020 only
source & licensing
fields
| name | type | definition |
|---|---|---|
| county_id | string | 5-character FIPS code identifying the county.Joins dim.counties on county_id. |
| state_id | string | 2-character FIPS code identifying the state.Joins dim.states on state_id. |
| zip_codekey | string | 5-digit ZIP Code Tabulation Area (ZCTA) as defined by the U.S. Census Bureau, approximating USPS ZIP code boundaries. Used as the left-hand join key to map postal geographies to county FIPS codes.Joins dim.crosswalk_zip_county on zip_code. |
joins
how to use this table
For each ZCTA, the county with the greatest arealand_part (land area of intersection) is selected. Rural ZCTAs that span multiple counties are assigned to the dominant county by area.
Exact ZIP-to-county mapping; ZCTAs are Census constructs that approximate postal ZIPs and may not match perfectly. Multi-county ZCTAs are assigned to one county only.