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Resource Library
Relationship Files
Relationship Files
These text files describe geographic relationships. There are two types of relationship files; those that show the relationship between the same type of geography over time (comparability) and those that show the relationship between two types of geography for the same time period.
Relationship files for 2020 do not include housing or population counts.
There are supplemental files (not relationship files) included on this page for Congressional Districts and State Legislative Districts. These are the urban/rural population and land area files and are only produced for these three geographies. Congressional Districts also have the land area file linked on this page.
Block Relationship Files
The 2020 Census Redistricting Data (P.L. 94-171) Block Relationship files are provided as a tool to help users compare the universe of 2010 Census tabulation blocks to the universe of 2020 Census tabulation blocks. The Block Relationship files are created for each of the 50 states, the District of Columbia, and the Commonwealth of Puerto Rico.
2010 Census Tabulation Block to 2020 Census Tabulation Block Relationship Files
Block Group Relationship Files
The 2020 block group relationship files provide simple relationships between 2020 block group entities and 2010 block group entities.
State-level 2020 Block Group to 2010 Block Group Relationship Files
Census Tract Relationship Files
The 2020 census tract relationship files provide simple relationships between 2020 census tract entities and 2010 census tract entities.
State-level 2020 Census Tract to 2010 Census Tract Relationship Files
County Subdivision Relationship Files
The 2020 county subdivision relationship files provide simple relationships between 2020 county subdivision entities and 2010 county subdivision entities.
State-level 2020 County Subdivision to 2010 County Subdivision Relationship Files
Place Relationship Files
The 2020 place relationship files provide simple relationships between 2020 place/census designated place (CDP) entities and 2010 place/CDP entities.
State-level 2020 Place to 2010 Place Relationship Files
2010 to 2020 Urban Areas Relationship Files
The 2010 to 2020 Urban Area relationship file provides relationships between the 2010 Census Urban Area entities and updated 2020 Census Urban Area entities.
ZIP Code Tabulation Areas (ZCTAs) Relationship Files
The 2020 Census ZIP Code Tabulation Areas (ZCTAs) Relationship file is provided as a tool to help users compare the universe of 2010 Census ZCTAs to the universe of 2020 Census ZCTAs.
Congressional District Relationship Files
The 2020 118th Congressional District relationship files provide simple relationships between the 2020 118th Congressional Districts entities and other 2020 Census tabulation geography.
State level 2020 118th Congressional District To 2020 AIANNH Relationship Files
State level 2020 118th Congressional District To 2020 Census Tract Relationship Files
State level 2020 118th Congressional District To 2020 County Relationship Files
State level 2020 118th Congressional District To 2020 County Subdivision Relationship Files
State level 2020 118th Congressional District To 2020 Place Relationship Files
State level 2020 118th Congressional District To 2020 School District Relationship Files
State level 2020 118th Congressional District To 2020 Zip Code Tabulation Area (ZCTA) Relationship Files
American Indian/Alaska Native/Native Hawaiian Area (AIANNH) Relationship Files
The 2020 American Indian/Alaska Native/Native Hawaiian Area (AIANNH) relationship files provide simple relationships between the 2020 AIANNH entities and other 2020 Census tabulation geography.
2020 State Legislative District-Lower Chamber (SLDL) Relationship Files
The 2020 SLDL Relationship files provide simple relationships between the 2020 SLDL entities for the 2022 legislative year and other 2020 Census tabulation geography.
State level SLDL To 2020 AIANNH Relationship Files
State level SLDL To 2020 Census Tract Relationship Files
State level SLDL To 2020 County Relationship Files
State level SLDL To 2020 County Subdivision Relationship Files
State level SLDL To 2020 Place Relationship Files
State level SLDL To 2020 School District Relationship Files
State level SLDL To 2020 Zip Code Tabulation Area (ZCTA) Relationship Files