youth using mobile phone

Frequently Asked Questions about the Census

2020 Census Overview

LUCA Overview

LUCA Tools

LUCA Execution

2020 Census Overview

1. What's important about the Census?

An accurate count of the U.S. population forms the basis for many important, but often overlooked political, economic, and social decisions that end up affecting our daily lives. Census data affects the number of seats each state occupies in the House of Representatives and people from many walks of life use census data to advocate for causes, rescue disaster victims, prevent diseases, research markets, locate pools of skilled workers and more. The information the census collects helps to determine how more than $400 billion dollars of federal funding each year is spent on infrastructure and services like:

  • Hospitals
  • Job training centers
  • Schools
  • Senior centers
  • Bridges, tunnels and other-public works projects
  • Emergency services

Census data is also key for protecting minority political representation through legislation like the Voting Rights Act and regular redistricting. 

As such, it’s critical to ensure that individuals are correctly counted in the 2020 Census so that cities, counties, and states can receive funding for programs to serve them.

2. How is Census data used?

Census data is used for:

  • Apportioning representation among states as mandated by Article 1, Section 2 of the US Constitution
  • Drawing congressional and state legislative districts, school districts and voting precincts
  • Enforcing voting rights and civil rights legislation
  • Distributing federal dollars
  • Informing planning decisions of tribal, federal, state and local government and organizational decisions (e.g., where to locate,size of market, etc.) of businesses and non-profitsImpact

Impact of the Census count on democracy:

  • As directed by the Constitution, the 435 seats in the House of Representatives are apportioned among the states on the basis of the Census count
  • The Census count determines the electoral college with the number of electors each state receives for presidential elections
  • States and localities redraw legislative boundaries that comply with standards for population equity ("one person, one vote") and racial and ethnic balance (Voting Rights Act, Sections 2 and 5).

Impact of the Census count on Civil Rights enforcement:

  • Census data provide key benchmarks for federal monitoring and enforcement of civil rights and anti-discrimination laws in voting, employment, housing, lending, and education.

Impact on distribution of funding:

  • Census data guides the flow of $400 billion annually in federal domestic assistance across the nation
  • Federal agencies use Census data to inform the design, implementation, and evaluation of programs and policies in every government realm, such as education, health, housing, transportation, small business development, human services, and environmental protection.
  • State and local governments rely on Census data to make decisions on the annual distribution of hundreds of billions of dollars for critical services.

As such, it’s critical to ensure that individuals are correctly counted in the 2020 Census so that they are properly represented and that cities, counties, and states can receive funding for programs to serve them.

3. What’s different about the 2020 Census?

The 2020 Census has updates to process and data, but is also hampered by limited resources:

2020 Census Design


Many of these updates are intended to address undercounting of individuals who are hard to reach, including new programs to work with trusted nonprofits and other organizations to inspire participation and using multiple data sources.

Budget cuts by Congress to the 2020 Census means that the U.S. Government Accountability Office has rated the 202 Census ‘High Risk,’ and the Census could result in substantial undercounting of low-income, underserved, and hard-to-reach households due to program reductions:

  1. Address Canvassing: The budget for address canvassing is reduced.
  2. Online Survey: Instead of traditional mail-in surveys, the 2020 Census will rely on an online survey.
  3. Fewer Enumerators: Instead of Census takers making multiple efforts to visit unresponsive households, the 2020 Census will reduce Census taker visits by half.
  4. Quality Enumerators: The labor market, if it is as good as it is currently, will make it harder for the government to recruit enough quality Census takers within their budget.
  5. Limited budget for advertising, partnerships, and language assistance.


Blocks for In-Person Address Canvassing





Regional Offices



Local Offices



Number of Enumerators



Number of In-person Enumeration Attempts



Sources: ; Census 2020 Operation Plan

Because of these cuts, new programs to address undercounting (like LUCA) are more important than ever for the 2020 Census.

4. How much funding is determined by the Census?

Census data guides the flow of $400 billion annually in federal domestic assistance across the nation, and state and local governments rely on Census data to make decisions on the annual distribution of hundreds of billions of dollars for critical services.

Missing addresses means big losses for local communities. In California, for instance, each person not counted is a loss of $1,958 annually for programs such as Medi-Cal, Head Start early childhood programs, and community health centers.​

With about three persons per housing unit in California, that is a loss of $6,000 per year in federal funding—in other words, $60,000 for each missed address for the 10 years that the Census count is in effect.

Here are examples for LA City and County:

LA county missed funding

LUCA Overview

1. What is LUCA?

LUCA stands for Local Update of Census Addresses, and it provides a voluntary opportunity for designated representatives of tribal, state, and local governments to review and comment on the addresses used to conduct the decennial census.

 In plain english, this means that tribal, state, and local governments can leverage the expertise and relationships of on-the-ground organizations (like nonprofits) to improve the accuracy and completeness of the Census count, especially as it pertains to hard-to-count households. This process is known as Community-based Address Canvassing (CBC). Conducting LUCA with the CBC process looks like the following:

  1. Local government and community-based-organizations (CBOs) work to select areas to canvas
  2. CBOs activate volunteers as enumerators and collect addresses in targeted areas
  3. CBOs submit addresses to local governments
  4. Local government reviews address information and submits to Census Bureau
  5. Census Bureau verifies addresses and revises the Master File as appropriate
2. How successful was LUCA in past years?

The Local Update of Census Addresses Program was an integral part of the 2010 Census activities that utilized the expertise of tribal, state, and local governments to improve the accuracy and completeness of the Master Address File, the Census Bureau’s national living quarters inventory. The Master Address File served as the basis for the address list used to take the 2010 Census.

Here are some high-level statistics around LUCA in 2010:

  • 29% of eligible governments (11K out of 39K) registered to participate
  • 39% of participants used a paper address list and paper maps to track updates
  • 8K (72%) of participants submitted address returns
  • 41M address records were processed, of which 9M were new ads to the master file


3. Who can participate in LUCA?

Active, functioning governments are eligible to participate in LUCA for areas including:

  • Federally recognized tribes with a reservation and/or off-reservation trust lands
  • States
  • Counties
  • Cities (incorporated place)
  • Townships (minor civil divisions)

If your government lacks the resources to participate in LUCA, you can arrange for a higher level of government, such as county, or an organization, such as regional planning agency or council of governments, to conduct your review.

4. Will the Census Bureau pay our government for participating in LUCA?

The Census Bureau cannot compensate for the completion of a LUCA review. Participation in the 2020 LUCA operation is voluntary. (Source:

With this said, cities and counties in some states can get state assistance for canvassing. For example, in California there is $7M in total funding available, with a large city (like San Francisco or San Jose) qualifying for around $100K in funding.

5. How does California determine how much funding to allocate?

A minimum of $7,500 will be available for each jurisdiction that applies for the incentive and participates in the program.  

The amount of the incentive each jurisdiction receives is based on the housing activity (building, demolitions and annexations) from April 1, 2010, to January 1, 2017, using estimates from the Demographic Research Unit. Additional funds may be added for jurisdictions which experienced a disaster area declaration since 2010. 

See the List of LUCA Incentive Awards for the specific minimum award for your jurisdiction.

The California Department of Finance will administer the LUCA incentive fund. There are three requirements to receive an award:

  1. Local governments must register to participate in the LUCA program with the U.S. Census Bureau.
  2. The deadline to register is December 15, 2017. If you cannot locate your forms, e-mail the Census Bureau immediately at
  3. To receive the incentive, local governments must participate in the LUCA Program and submit required materials to the Census Bureau. Materials will be sent out in the first quarter of 2018.Local governments must request incentive funds from the Department of Finance. Jurisdictions that have registered for LUCA with the Census Bureau will receive instructions on how to request incentive funds in early 2018.
6. What are the confidentiality and security requirements for LUCA?

Information provided to/from LUCA is covered under Title 13 of the United States Code which:

  • Requires the Census Bureau to ensure confidential treatment of census-related information, including individual addresses and map structure points
  • Requires all liaisons, reviewers, and anyone with access to Title 13 materials abide by Confidentiality and Security Guidelines
  • Requires the Census Bureau maintain the confidentiality of all information it collects

The Census Bureau recommends using a stand-alone computer, not connected on your existing network to complete your LUCA review. Transfer source information to this computer while still on your network or via USB flash drive or CD/DVD and then disconnect the computer from the network prior to beginning your review. Saving your LUCA work to a USB flash drive or a location on your computer’s hard drive that is not automatically backed-up to a server, minimizes the risk of losing data if the system crashes or data becomes corrupted.

The Confidentiality and Security Guidelines can be found here:


7. How do I register for LUCA?

See the most up to date information from the Census Bureau at

8. How does a government prepare for LUCA?

Your government can prepare for 2020 LUCA in the following ways:

  • Review and become familiar with the content on the 2020 LUCA Web site:
  • Plan to attend a 2020 LUCA Training workshop (October 2017 - February 2018).
  • Ensure you designate the proper person as LUCA liaison to guide the entire review process.
  • Determine and assemble your local address sources (e.g., E911 data, appraisal or assessor data, planning and zoning records, utility records, building permits, voter registration records, drivers’ license records, other GIS address source information, etc.).
  • Separate commercial from residential addresses within your address list.
  • Update your address list with multiunit structure identifiers (e.g., Apt 1, Unit C, #300, etc.).
  • Download and review (or print) the 2020 Census LUCA Address Count file for your government from the 2020 LUCA  website.
  • Geocode* your local, digital-format address list using the Census Geocoder linked on the 2020 LUCA website. *Geocodes assign the geographic location (state, county, tract and block codes) to individual addresses.
  • Once geocoded, use your local address list to generate your own address count tallies for comparison to the Census Bureau’s tallies displayed in the Address Count list. This may require a download of census blocks from
  • Develop a plan to target specific areas (ex. blocks around boundary, areas of new development, areas of transition or zoning change, etc.) and/or specific addresses (ex. group quarters addresses, multiunit addresses, mobile home parks, address conversions, etc.) within your government to help focus your review.
9. What’s the LUCA schedule?


January 2017:  Advance notification of LUCA mailed to the Tribal Chairpersons (TCs) and Highest Elected Officials (HEOs) of all eligible governments and other LUCA contacts.

March 2017:  LUCA promotional workshops began.

July 2017:  Invitation letter and registration forms mailed to the TC and HEO of all eligible governments.

October 2017:  Training workshops begin. Self-training aids and Webinars will be available online at the LUCA website.

December 2017:  Deadline to register for LUCA.

February 2018:  Participation materials (including Census Bureau Master Address File) mailed to registered participants.

Deadline for Submitting Addresses: Once a city or county gets the Census Bureau Master Address File, the clock starts ticking and they have 120 days to submit additional addresses

August 2019:  Feedback materials offered to participants with the results of address canvassing.

April 1, 2020:  Census Day.

10. Does the Census offer resources for LUCA training?

The Census Bureau maintains a schedule of LUCA training and promotional workshops at

If you are unable to attend a LUCA promotional workshop, you can view the LUCA promotional webinar presented to the Kentucky Association of Mapping Professionals on April 27, 2017 here:

11. How significant is the undercount of the addresses in the Census Master Address File?

The undercounting problem stems from three areas:

1. Census relying on satellite and administrative records (e.g., IRS) rather than in-field canvassing

  • Satellite images miss many unconventional arrangements (e.g., converted garages and some trailers)
  • Many people may not be captured with Federal administrative records, but may be included in local records

2. Increasing pressure for unconventional housing

  • Rising rents mean more pressure for unconventional housing arrangements
  • Current political environment for undocumented means they are unlikely to share data with federal officials

3. Very short window for local governments to review and add addresses

  • Need to prepare prior to receiving official MAF

Data from past Census and other sources shows that the undercounting problem is real and significant:

LA undercounted population numbers

Sources: US Census American Factfinder ; California Department of Finance Report E-4

California Department of Finance incorporates their own administrative data - in particular driver’s licenses into their estimates. Many cities like New York and SF have challenged the Census regarding the accuracy of the count.

LUCA Tools

1. What tools are available to assist with LUCA?

The Census Bureau provides a number of feedback products if you participate in LUCA:

The 2020 LUCA feedback materials include an updated address list, address count list and maps in the same format as the original 2020 LUCA materials. In addition, the Census Bureau will provide a detailed feedback list that summarizes the actions taken by the Census Bureau for each address submitted by your government as part of its 2020 LUCA submission. As with the original 2020 LUCA materials, Title 13U.S.C. protection applies to these materials as well.

The Geographic Update Partnership Software, or GUPS, is a self-contained, customized GIS software tool provided by the Census Bureau for participation in a variety of Census geography programs, including 2020 LUCA. Pre-packaged to include all of the components for 2020 LUCA, the GUPS contains the Census Bureau’s address list, address count list, and TIGER partnership shapefiles. GUPS allows the participant to add external geospatial data (shapefiles, geodatabases, and imagery) for comparison and update purposes. Delivery of all data (software, address list, address count list and shapefiles) is on DVD. Please note that although GUPS provides the ability to import a local, digital address list, there is no address matching capability provided between the Census Bureau’s address list and the local address list in GUPS.

Designed with the participant in mind, GUPS is user-friendly. It allows for simple to complicated LUCA reviews and edits. Programmed with a review tool requiring the user to validate their edits before creating a submission file, GUPS ensures the file(s) submitted are valid and allows for easier processing once received by the Census Bureau. GUPS does not require an internet connection, but one is necessary to use the imagery server. 

Census Outreach SMS based tools are an excellent supplement to the Census Bureau’s own tools. Our tools are designed for community-based address collection in partnership with local nonprofits.


2. How does Community Connect help with LUCA?

Community Connect Labs provides text-message based tools for governments conducting community-based outreach to use to submit GPS data and descriptions for addresses to add to the master file. Addresses submitted through our tool are formatted as a LUCA-friendly CSV for easy review and submission to the Census.

3. What is the Census Geocoder?

The Census Geocoder is an address look-up tool that converts your address to an approximate coordinate (latitude/longitude) based on the address ranges found within the TIGER/Line shapefiles. It returns information about the address range where the individual address falls and includes the state, county, tract, and block codes (also known as geocode information). 

The Census Geocoder works for an individual address or batch file of up to 10,000 addresses. The information in the geocoder comes from the Census Bureau’s Master Address File / Topologically Integrated Geographic Encoding and Referencing (MAF/TIGER) system, which holds the geographic information used for censuses and surveys. Derived from the MAF, the address ranges used in the geocoder are the same address ranges found in the TIGER/Line shapefiles. 

There are limitations to the address ranges found in the MAF/TIGER system. The address ranges are potential address ranges, not actual address ranges. Potential ranges include the full range of possible structure numbers even though the actual structures may not exist. The majority of address ranges we have are for residential areas. There is limited availability of address ranges in commercial areas. The Census Bureau updates the address ranges regularly with the most current information available 


LUCA Execution

1. What are examples of unconventional addresses?

See below for examples of unconventional addresses:

  • Garages
  • Basements
  • Workshops
  • Trailers
  • Backs of retail shops
  • Sheds behind a main house
garage turned another housing unitRV trailer inside a propertyRV trailer in parking area
2. What if the household address is collected by the Community-Based Address Canvassing, but the residents do not answer the census form, or do not open their door to the census enumerator?

Even if no one in the household responds, but there are signs that people live in a housing unit, the Census Bureau will "impute" the existence and number of people living at the address in question, a procedure known as “count imputation.” In 2010, according to figures supplied by the Census Bureau, 1,163,462 people were added to the household population via count imputation.

When the household does not respond to the census survey, an Enumerator will be sent to the housing. If no one answers the door, the Enumerator will ask neighbors if they know how many people live in that unit. If no information is available from neighbors, but there are signs of occupancy, the Census Bureau will impute the number of people who live there.