These Block Equivalency Files (BEFs) are the whole 2020 Census tabulation block representations of the 120th Congressional District plans as submitted by the states to the U.S. Census Bureau. The .ZIP file contains a national block equivalency file and individual state files for the ten states (Alabama, California, Florida, Louisiana, Missouri, North Carolina, Ohio, Tennessee, Texas, and Utah) that redrew their congressional district plans for the 120th Congress. The fields in these files should be imported as text to preserve leading zeros.

In instances where plans included split 2020 Census tabulation blocks, the Census Bureau requested that the state assign the whole block to one district for the purpose of tabulating data. These block equivalency files contain the whole block tabulation plan.

Only one state--Colorado--split blocks in their 120th Congressional District plan. Colorado split one block, 080010096072000, between Congressional District 07 and Congressional District 08. The data for that census block will be tabulated to Congressional District 08. This is unchanged from Colorado's 118th and 119th Congressional District plan.

1) The block equivalency files are based on the original 2020 Census tabulation blocks as they appeared in the official 2020 Census Data Products. If you are working with geographic data created after the 2020 Census—such as shapefiles, GeoDatabases, or online viewers like TIGERWeb—you may notice slight differences between the blocks shown in these products and those from the original 2020 Census products (and used to create these BEFs).

These differences occur when block boundaries were updated after 2020 for greater spatial accuracy. For example, if a block boundary follows a road or the edge of an incorporated place, and that road or boundary is adjusted to better match real-world features, the block boundary will change as well. The blocks released with the 2020 Census reflect their original shapes, and jurisdictions their 2020 boundaries, while blocks and jurisdictions in post-2020 products (also known as “current blocks” or "current geography") show any updates made since then.

2) Congressional districts are identified by a 2‐character numeric FIPS code. Congressional districts are numbered uniquely within state. The District of Columbia and Puerto Rico have the code of 98, which identifies their status with respect to representation in Congress:

• 01 to 53—Congressional district codes
• 00—At large (single district for state)
• 98—Nonvoting delegate

3) In Connecticut, Illinois, and New Hampshire the state did not assign the current congressional districts to cover all of the state or equivalent area. The code “ZZ” has been assigned to areas with no congressional district defined (usually large water bodies). These unassigned areas are treated within state as a single congressional district for purposes of data presentation.