How did Massachusetts lose or gain congressional seats after the 2020 census?

Checked on December 8, 2025
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Executive summary

Massachusetts neither lost nor gained seats after the 2020 census: the state was apportioned nine U.S. House seats, the same number it held after the 2010 census [1] [2]. The state’s April 26, 2021 apportionment count put Massachusetts at about 7.03 million residents, a 7.4% increase over 2010 that was sufficient to preserve the nine-seat delegation [1] [3].

1. How apportionment worked this cycle — quick facts

Apportionment divides the 435 House seats among states based on the decennial census counts; the Census Bureau’s 2020 apportionment results released April 26, 2021 showed Massachusetts kept nine seats [4] [1]. The state’s total population for the apportionment was reported as 7,029,917, up 7.4% from 2010, which placed Massachusetts safely above the threshold that would have cost it a seat [1] [3].

2. Why some observers expected a risk of losing a seat

Massachusetts had a modern history of declining delegation size: the state lost seats repeatedly across earlier decades and lost one seat after the 2010 census, dropping from ten to nine, which fed concern in 2020 that another loss was possible [5] [6]. State officials publicly worried the pandemic and operational challenges could undercount populations—particularly students and immigrants—so Secretary of the Commonwealth William Galvin emphasized the stakes and monitored the bureau’s work closely [3] [7].

3. What actually changed on the map — redistricting, not apportionment

Although the number of seats did not change, Massachusetts still underwent a full redistricting to rebalance district populations and to reflect internal population shifts; the General Court and governor enacted new congressional maps in late 2021 that took effect for the 2022 elections [8] [2]. Redistricting adjusted boundaries — for example, the 1st and 6th districts were shifted in scope — but did not alter the statewide count of nine seats [9] [10].

4. Political consequences: stability rather than upheaval

Because Massachusetts retained nine seats, the principal contest became how districts were drawn, not whether a seat would vanish. The 2022 elections under the new maps produced the same nine-member delegation, all Democrats, which observers say reflects both the map and the state’s partisan geography [11] [5]. Ballotpedia and local reporting note that redistricting decisions rather than apportionment produced the main political debates in 2021 [8] [2].

5. Broader national context: seats moved elsewhere

Nationwide, seven seats shifted among 13 states due to differing growth patterns — fast-growing Sun Belt and Mountain West states gained seats while slower-growing states like New York and California lost seats — but Massachusetts was not among the gainers or losers in that redistribution [6] [4]. States that gained seats included Texas (two seats), Florida, and others; states losing seats included California, New York and Pennsylvania [6].

6. Limits of available reporting and remaining disputes

Available sources do not mention any credible post-apportionment reversal that changed Massachusetts’s nine-seat allocation after April 26, 2021; reporting focuses on redistricting litigation and map enactment rather than a later apportionment change [8] [2]. Some local officials argued vigorously during 2020–21 that undercounts could cost the state a seat and said they would challenge federal procedures if necessary, but the apportionment ultimately preserved nine seats [3] [7].

7. Bottom line for readers

Massachusetts kept nine U.S. House seats after the 2020 census because its population grew to about 7.03 million — enough to retain the delegation size established after 2010 — and the consequential fight shifted from apportionment to how those nine districts would be drawn for the next decade [1] [3] [8].

Want to dive deeper?
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How does the apportionment formula determine if a state like Massachusetts gains or loses House seats?
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