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INSIGHTi
Apportionment and Redistricting Following
the 2020 Census
Updated March 17, 2021
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. 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 with
relatively equal-sized populations for each House district.
Timelines for the census and apportionment are provided in federal statute and general y occur as
scheduled every decade. The Coronavirus Disease 2019 (COVID-19) pandemic, however, affected 2020
census field operations and delivery of apportionment figures; concerns remain 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 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. A count
known as the apportionment population, which reflects the total resident population in each state, 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 is to report the apportionment population to the
President; the Census Bureau has often released apportionment counts publicly at about the same time.
According to this timeline, within the first week of the first regular session of the next Congress, the
President transmits a statement to Congress with information on how to apportion House seats. The
President’s message 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.
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The Clerk of the House sends each governor a certificate indicating a state’s number of Representatives
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; 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 prevented the delivery of figures as scheduled and have led to questions about possible effects
on state redistricting processes expected to begin in 2021. On January 27, 2021, the Census Bureau
announced apportionment counts would be completed April 30, 2021; on February 12, 2021, the Bureau
announced states would receive redistricting data by September 30, 2021.
Context for 2020 Delays
As the COVID-19 pandemic began in early 2020, some advocated that adjustments to census operations
were necessary to provide an accurate, complete count while protecting the health of respondents and
census workers. On March 18, 2020, the Census Bureau announced its first temporary suspension of 2020
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field operations. Further changes announced April 13 included closing field offices through June 1, and a
proposed timeline that would have extended data collection through October 31, 2020. 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 as requested by states no later than July 31,
2021. Four former bureau directors wrote a letter supporting census extensions.
The Census Bureau postponed certain 2020 census deadlines. 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 2020 that would have adjusted the statutory deadlines, but none was enacted:
H.R. 6800 (passed the House), H.R. 7034, and S. 4048.
Through the end of 2020, some continued to express concerns over the accuracy and completeness of
collected census data and the bureau’s ability to provide apportionment figures by its statutory deadline. A
House Committee on Oversight and Reform hearing on December 3 addressed census data anomalies and
potential delivery delays. During fal 2020, a pending case before the U.S. Supreme Court regarding a
July 2020 presidential memorandum related to excluding unauthorized immigrants from the
apportionment population reportedly could have affected the timing of apportionment delivery; the Court
dismissed the chal enge to the memorandum on December 18, 2020.
Possible Redistricting Effects
The delay of apportionment data delivery has raised some concerns about possible effects on
congressional and state legislative redistricting. Many states had begun (and some had completed)
redistricting by July 2011 following the 2010 census. A number of states, particularly those with
constitutional or statutory redistricting deadlines in 2021, might face chal enges following the 2020
census. Solutions available for states vary, depending on when apportionment and redistricting data are
provided; what the state’s redistricting process is; and what options are available under state law and
practice to modify the redistricting process or related election matters. This could, general y, include
options such as postponing certain redistricting deadlines, candidate filing deadlines, or primary election
dates; states might also seek judicial relief from redistricting deadlines in current law. States with part-
time legislatures or 2021 elections may face additional chal enges. In November 2020, New Jersey voters
approved a constitutional amendment al owing use of existing state legislative district maps for the state’s
November 2021 general election.
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
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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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