The decennial census is the single largest civilian governmental undertaking in the United States.
Census data is the starting point for congressional apportionment—how many seats in the U.S. House of Representatives each state is allotted each decade—and for redistricting—the redrawing of all types of electoral boundaries to account for population changes and ensure near-equal populations in those districts. Historically, hundreds of federal programs have allocated billions of dollars to states and localities based on census-generated population figures.
Although the census is the federal government's responsibility, state legislatures can provide important support early in the decade to ensure the census is based on accurate geography. Later in the decade, state legislatures can take action to ensure that citizens are prompted to participate in the census.
Already, the U.S. Census Bureau is launching several programs allowing states to submit geographic data they want to be reflected in the 2030 census. State participation in these programs is voluntary and can contribute to increased accuracy when census results are released.
States that want to ensure the Census Bureau's enumeration-and the final census data-is based on accurate geographic information can engage with the Census Bureau through several voluntary programs leading up to the census. Beginning as early as 2026, these include:
- The Redistricting Data Program (RDP)
- The Block Boundary Suggestion Program (BBSP)
- The Voting District Project (VTDP)
- The Local Update of Census Addresses program (LUCA)
- The Boundary and Annexation Survey (BAS)
These programs give states and localities the opportunity to collect information about geographic boundaries and residential addresses and submit that data to the Census Bureau for review. The Redistricting Data Program and the Boundary and Annexation Survey help ensure that census data accurately aligns with legal and administrative geographic boundaries in the states. Meanwhile, the Local Update of Census Addresses gives the Census Bureau information to help finalize the list of addresses census takers will canvass. The Redistricting Data Program and its Block Boundary Suggestion Project and Voting District Project are housed within the Census Bureau's Redistricting and Voting Rights Data Office, while the Local Update of Census Addresses and the Boundary and Annexation Survey are administered within the Census Bureau's Geography Division. States may have contact points with multiple Census Bureau officials in multiple offices for questions about different programs.
States vary in how they collect and share information through these programs. Legislative or other state or local government staff may be assigned to various aspects of this work. For example, when it comes to the Block Boundary Suggestion Project and the Voting District Project, a state designated official may provide all the updates or they may provide instructions and resources to localities, receive and collate their feedback and transmit it to the Census Bureau. Alternatively, localities may be asked to lead the charge to collect geographic data and submit that information to their state liaison, who sends the information on to the bureau.
State and local officials and staff can meet with Census Bureau officials to learn more before preparation for the 2030 census begins. See Your Checklist: Questions for Legislators and Legislative Staff at the bottom of this page for how you can get your state involved in these programs.