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INSIGHTi
Apportionment and Redistricting Following
the 2020 Census
Updated December 9, 2020
The census, apportionment, and congressional redistricting are interrelated processes that occur every
decade. The U.S. Constitution provides that a decennial census determines the distribution of U.S. House
seats across states, though the federal government today also uses census data for other purposes, such as
distributing funding to states and localities. The process of dividing House seats across states is known as
apportionment (or reapportionment). Each state must receive one House seat and additional seats are
distributed proportional y based on state population size. States then engage in redistricting, creating or
redrawing geographic subdivisions for each House district with relatively equal-sized populations.
Timelines for the census and apportionment are provided in federal statute and general y occur as
scheduled every decade. The COVID-19 pandemic, however, affected 2020 census field operations, and
raised concerns about timing for the apportionment and redistricting processes that follow the completion
of the census. This Insight provides background on the typical timing of the census, apportionment, and
redistricting, as wel as a brief discussion of recent 2020 census operational changes and proposals,
particularly those related to the subsequent congressional apportionment and redistricting.
Typical Timing—Census, Apportionment, and
Redistricting
Figure 1 il ustrates a timeline of the typical census, apportionment, and redistricting processes. Federal
statute requires that April 1 of any year ending in “0” marks the official decennial census date, although
the Census Bureau begins certain population counts and outreach earlier. A count known as the
apportionment population, which reflects the total resident population in each state (including minors and
noncitizens, in addition to Armed Forces and federal civilian personnel and their dependents living
abroad), is typical y used to distribute House seats. Within nine months of the decennial census date
(December 31 of the year ending in “0”), the Secretary of Commerce reports the apportionment
population to the President. The Census Bureau has, in past years, released apportionment counts publicly
at about the same time.
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Within the first week of the first regular session of the next Congress, the President transmits a statement
to Congress that provides information on how to apportion House seats. The President’s message to
Congress contains the apportionment population and resulting number of Representatives for each state,
based on the total number of Representatives (435) and using the method of equal proportions.
The Clerk of the House sends each governor a certificate indicating the number of Representatives for
their state within 15 calendar days of receiving the President’s apportionment message. Each state
receives the number of Representatives noted in the President’s statement, beginning at the start of the
next session of Congress (typical y, early January of a year ending in “3”). States may then engage in their
own redistricting processes before the start of that Congress, and the timing of redistricting varies based
on state laws.
Figure 1. Typical Timeline of Census, Apportionment, and Redistricting Process
Source: CRS compilation, based on information from the U.S. Constitution, U.S. Code, U.S. Census Bureau, and state laws.
Graphic created by Amber Hope Wilhelm, CRS Visual Information Specialist.
Recent Developments
Census delays due to the COVID-19 pandemic and issues related to compiling the apportionment
population have led to questions about possible effects on the apportionment and redistricting processes
following the 2020 census.
Census operations for 2020 were underway as the COVID-19 pandemic began. Many Americans used the
internet, phone, or mail to provide timely self-responses to the census, but the Census Bureau’s in-person
field operations, which collect data for certain remote communities and follow up with nonrespondents,
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presented public health concerns. In March and April 2020, some advocated that operational adjustments
were necessary to provide an accurate, complete count while protecting the health of respondents and
census workers.
On March 18, the Census Bureau announced its first temporary suspension of 2020 field operations.
Further changes announced April 13 included closing field offices through June 1, and a proposed
timeline that would extend data collection through October 31. This schedule also proposed delivery of
apportionment counts to the President by April 30, 2021 (to be delivered to Congress within 14 days of
receipt) and delivery of redistricting data in response to state requests no later than July 31, 2021. Four
former Census Bureau directors wrote a letter in support of the census extensions.
The Census Bureau postponed certain deadlines for the 2020 census. Operating under a revised schedule,
and following a U.S. Supreme Court ruling, the bureau accepted responses until October 15, two and a
half months later than usual. To date, Congress has not changed the statutory deadlines for the bureau to
deliver apportionment data to the President or redistricting tabulations to states. Three bil s were
introduced in May and June that would have adjusted the statutory deadlines to meet the Census Bureau’s
proposed deadlines, but they have not become law: H.R. 6800 (passed the House), H.R. 7034, and S.
4048.
Some have continued to express concerns over the accuracy and completeness of collected census data
and the Census Bureau’s ability to provide apportionment data by its statutory deadline. The House
Committee on Oversight and Reform held a hearing on December 3 addressing census data anomalies and
potential delays for data delivery. Media reports indicate that the bureau might not be able to deliver
apportionment counts on time, possibly until late January 2021. The outcome of a case before the
Supreme Court on whether to exclude unauthorized immigrants from the apportionment population (as
directed by a July 2020 presidential memorandum) reportedly might also affect when apportionment data
are provided.
The potential delay of apportionment data delivery has raised some concerns about possible effects on
congressional redistricting. For example, following the 2010 census, many states had begun (and some
had completed) redistricting by July 2011. States with constitutional or statutory redistricting deadlines in
2021, and especial y those with part-time legislatures or 2021 elections, might face particular chal enges
if apportionment or redistricting data from the Census Bureau are not received when expected.
Author Information
Sarah J. Eckman
Analyst in American National Government
Disclaimer
This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff
to congressional committees and Members of Congress. It operates solely at the behest of and under the direction of
Congress. Information in a CRS Report should not be relied upon for purposes other than public understanding of
information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role.
CRS Reports, as a work of the United States Government, are not subject to copyright protection in the United
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