For Phase 3 – Data Delivery, the Director of the Census Bureau, in accordance with 13 U.S.C. 141(c), furnished the Governor and state legislative leaders, both the majority and minority, with 2020 Census population counts for standard census tabulation areas (e.g., state, Congressional district, state legislative district, American Indian area, county, city, town, census tract, census block group, and census block) regardless of a state’s participation in Phase 1 or 2. In addition, for those states participating in Phase 2, standard census tabulation were provided for voting districts.

As a lesson learned from past decennial censuses, it was vital that the Census Bureau produce a prototype product to illustrate what the states should expect from the decennial census. This prototype was used to build and test systems in advance of the official data release so that states could begin work immediately, as many have short statutory deadlines that begin with the receipt of their data. In 2019, we used the prototype data product to illustrate and solicit feedback on what the 2020 Census P.L. 94-171 Redistricting Data File would look like and how it addressed the needs of the states for their legislative redistricting requirements.

These materials have been moved to the Decennial Census P.L. 94-171 Redistricting Data page.

After receipt of the official redistricting data, the 50 states, the District of Columbia (DC), and the Commonwealth of Puerto Rico (PR) began redrawing and adopting their post-2020 Census congressional and legislative district plans. During Phase 4, the Redistricting Data Program invites the 50 states, DC, and PR to provide those newly adopted congressional and legislative district plans to the Census Bureau.

Phase 4 is conducted in two cycles, the initial delineation cycle and the verification cycle. During initial delineation, states have the opportunity to provide their newly adopted plans to the Census Bureau. The Census Bureau loads the newly adopted plans into our geographic database, extracts the newly adopted plans from the geographic database, and sends the redistricting plans back to the states for a final verification. During verification, the states have the opportunity to review, provide feedback, and approve the redistricting plans as reflected in our geographic database. Once the plans are approved by the states, the Census Bureau will use these new boundaries in upcoming data products from both the 2020 Census and the American Community Survey (ACS). This process is repeated for each congressional session, collecting any congressional or legislative boundary changes that have occurred since the previous collection.

Phase 4 instructions and materials were provided to assist the official state non-partisan liaisons with their submission of the 119th Congressional and 2024 State Legislative District boundaries to the Census Bureau.