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What to Consider if You Find an Unexpected Census Result

Overall, we found that the 2020 Census results and redistricting data are comparable to the population benchmarks we've examined.

Our state and national level coverage measurement estimates also strongly indicate that the 2020 Census data are fit for use, including informed decision-making and painting a portrait of our nation’s people.

However, if you identified an unexpected census result, your governmental unit can contact the Census Bureau about the three options described below.

While reviewing these options, we encourage you to consider several factors, also listed below, that may explain why the census result is different than expected.

Options for Reviewing 2020 Census Counts

The Census Bureau offers two options for governmental units to request a review of their 2020 Census counts: Count Question Resolution (CQR) and 2020 Post-Census Group Quarters Review (PCGQR).

Count Question Resolution (CQR)

What is CQR? The CQR operation is an opportunity for governmental units to request a review of their boundaries and housing counts to determine whether errors occurred while processing 2020 Census counts.

When to consider requesting a CQR review? The CQR mechanism is an option for governmental units that believe their unexpected population total is due to incorrect legal boundaries or housing placement.

What can CQR provide?

If the CQR review identifies errors, the Census Bureau will issue corrected housing and population counts. These corrected counts can be used as official population totals, but they will not change 2020 data products, including apportionment results or redistricting data.

Corrected counts will be incorporated into the Census Bureau's population estimates base as the production schedule allows. This base is used to produce upcoming annual population estimates, and these estimates are used to develop the survey controls for the American Community Survey and the Puerto Rico Community Survey.

When can governmental units submit cases for review?

January 03, 2022 through June 30, 2023

Have questions? Visit our CQR webpage or email dcmd.2020.cqr.submissions@census.gov

2020 Post-Census Group Quarters Review (PCGQR)

What is the 2020 PCGQR? The 2020 PCGQR operation is a new, one-time operation for governmental units to request a review of their 2020 Census population counts for group quarters facilities. It was created in response to public feedback received on the Count Question Resolution operation about counting group quarters’ populations during the unprecedented challenges posed by the COVID-19 pandemic.

When to consider requesting a case for 2020 PCGQR? The 2020 PCGQR operation is an option for governmental units who believe that populations at group quarters facilities were counted incorrectly during the 2020 Census operation.

What can the 2020 PCGQR provide?

If the 2020 PCGQR review identifies discrepancies, the updated counts will be incorporated into the Census Bureau's population estimates base as the production schedule allows. This base is used to produce upcoming annual population estimates, and these estimates are used to develop the survey controls for the American Community Survey and the Puerto Rico Community Survey.

Population counts updated through 2020 PCGQR can be used as official population totals, but they will not change 2020 Census counts or data products, including apportionment results, or redistricting data.

When can governmental units submit cases for review?

June 06, 2022 through June 30, 2023

Have questions? Visit our PCGQR webpage or contact us at dcmd.2020.pcgqr.submissions@census.gov.

Post-Census Program for Updating Population Counts

For governmental units that require updated population counts between decennial censuses, the Census Bureau offers a Special Census Program. This program cannot review nor change 2020 Census counts, and it cannot alter 2020 Census data products such as apportionment results or redistricting data.

Special Census Program

What is Special Census? The Special Census Program conducts a basic enumeration of population, housing units, group quarters and transitory locations conducted between decennial censuses. The Census Bureau conducts this enumeration at the request of a governmental unit and the governmental unit pays for all costs. 

When to considering requesting a special census? A special census is an option for governmental units that believe their community’s population size or demographic composition changed considerably after the 2020 census.

What can a special census provide?

The Census Bureau will issue a certified, updated population count that corresponds to the reference date of the special census. 

These updated counts will be incorporated into the next series of annual population estimates that the production schedule allows. A special census, by design, has a reference date after April 1, 2020, so these updated counts will not be included in the base used to calculate population estimates.

When can governmental units submit a request for a special census?

The program expects to start accepting cases in March 2023.

Have questions? Visit our Special Census webpage or contact us at dcmd.Special.Census@census.gov

Why Your Census Result May Be Different than Expected

Although the Census Bureau considers the 2020 Census data fit for use based on population benchmarks and coverage measurement estimates, data users may still find results they did not expect in certain areas, particularly small geographies. These unexpected results may be explained by the factors below.

The 2020 Census results reflect where the population was living on April 1, 2020, the census reference date. Population changes since then (such as people temporarily relocating during the COVID-19 pandemic) are generally not reflected in the census.

If you are comparing population or housing numbers that represent a different timeframe, the numbers may differ from the 2020 Census results.

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The census generally counted people where they usually lived and slept as of April 1, 2020.

For example, seasonal residents are likely not included in your community’s count if they spend most of the year elsewhere. Instead, you may see vacant housing units that are counted as “for seasonal, recreational or occasional use” when we release detailed data on vacancy status. Other living situations also affect where people are counted.

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If group quarters in your community faced a change in circumstances by the reference date of the census, the census count could be different than expected. For example, a prison may have transferred some prisoners to another location at the onset of the COVID-19 pandemic, resulting in a smaller population size on April 1, 2020.

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Each decade, the census reflects the demographic changes that have occurred over the span of 10 years – including some changes not measured by our annual population estimates. We typically interpret differences between the estimates and census counts as error in the estimates and not the census counts.

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2020 Census data products reflect legal governmental unit boundaries in effect as of January 1, 2020. These boundaries are reviewed and updated through the annual Boundary and Annexation Survey (BAS). The Boundary Validation Program was also conducted in 2020 to provide governmental units with a final opportunity to review boundaries before the tabulation of census data.

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We inject statistical noise to protect individuals’ information and ensure confidentiality in published census statistics and data products. This noise is designed to make census block data appear “fuzzy” so that specific individuals and households cannot be identified. This protection may contribute to unexpected results down to the census-block level. More information about this subject is available in a recent Fact Sheet.

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