What are the fastest-growing counties in Massachusetts?
Hampshire County is the fastest-growing county in Massachusetts: its population grew 2.00% a year from 2020 to 2025, to 164,065 residents (Census PEP Vintage 2025). Nantucket County (0.72%) and Worcester County (0.72%) follow. Massachusetts as a whole grew 0.48% a year to 7,154,084 residents.
Data as of 2026-09-23. Population, growth and migration: PEP Vintage 2025 · 2020–2025. Income migration: IRS SOI 2022–2023 (2-yr lag).
Top 10 counties in Massachusetts by population growth, 2020 to 2025
| Rank | County | Population | Growth (% per year) | Net domestic migration | Net international migration | IRS net AGI migration |
|---|---|---|---|---|---|---|
| 1 | Hampshire County | 164,065 | 2.00% | +16,657 | +3,022 | -$28.0M |
| 2 | Nantucket County | 14,758 | 0.72% | -263 | +425 | -$16.2M |
| 3 | Worcester County | 888,502 | 0.72% | -4,343 | +30,997 | -$201.3M |
| 4 | Plymouth County | 546,829 | 0.69% | +4,574 | +13,657 | +$93.8M |
| 5 | Dukes County | 21,219 | 0.61% | -433 | +1,103 | +$12.0M |
| 6 | Bristol County | 593,640 | 0.58% | +4,779 | +14,406 | -$71.9M |
| 7 | Middlesex County | 1,669,979 | 0.55% | -61,446 | +88,643 | -$1.48B |
| 8 | Barnstable County | 233,539 | 0.48% | +8,500 | +6,086 | +$181.5M |
| 9 | Essex County | 826,653 | 0.46% | -20,560 | +33,438 | -$106.7M |
| 10 | Norfolk County | 739,749 | 0.44% | -12,498 | +23,916 | -$584.9M |
Where are people moving in Massachusetts?
Hampshire County gained the most people from elsewhere in the United States: net domestic migration of +16,657 from 2020 to 2025 (Census PEP Vintage 2025). The table ranks every Massachusetts place with 10,000 or more residents by that figure; the IRS column shows net adjusted gross income migration for 2022 to 2023.
| Rank | County | Population | Growth (% per year) | Net domestic migration | Net international migration | IRS net AGI migration |
|---|---|---|---|---|---|---|
| 1 | Hampshire County | 164,065 | 2.00% | +16,657 | +3,022 | -$28.0M |
| 2 | Barnstable County | 233,539 | 0.48% | +8,500 | +6,086 | +$181.5M |
| 3 | Bristol County | 593,640 | 0.58% | +4,779 | +14,406 | -$71.9M |
| 4 | Plymouth County | 546,829 | 0.69% | +4,574 | +13,657 | +$93.8M |
| 5 | Berkshire County | 128,224 | -0.25% | +652 | +1,909 | +$21.1M |
| 6 | Franklin County | 70,698 | -0.07% | +624 | +636 | +$8.9M |
| 7 | Nantucket County | 14,758 | 0.72% | -263 | +425 | -$16.2M |
| 8 | Dukes County | 21,219 | 0.61% | -433 | +1,103 | +$12.0M |
| 9 | Worcester County | 888,502 | 0.72% | -4,343 | +30,997 | -$201.3M |
| 10 | Hampden County | 464,338 | 0.03% | -7,339 | +9,207 | -$140.2M |
Go past the headline numbers
The interactive Demographics map layer and the full report for a single place are part of paid plans.
Get the Demographics Report for Hampshire CountyFrequently asked questions
- What are the fastest-growing counties in Massachusetts?
- By population growth from 2020 to 2025, the fastest are Hampshire County (2.00% a year), Nantucket County (0.72% a year), Worcester County (0.72% a year), Plymouth County (0.69% a year) and Dukes County (0.61% a year) (Census PEP Vintage 2025). Only places with 10,000 or more residents are ranked.
- Where are people moving in Massachusetts?
- By net domestic migration from 2020 to 2025, the largest gains are Hampshire County (+16,657), Barnstable County (+8,500) and Bristol County (+4,779) (Census PEP Vintage 2025).
- How fast is Massachusetts growing overall?
- Massachusetts grew 0.48% a year from 2020 to 2025, to 7,154,084 residents, with net migration of +140,575 people (Census PEP Vintage 2025).
- Where does this Massachusetts data come from, and how current is it?
- Population, growth and migration come from the U.S. Census Bureau Population Estimates Program (PEP Vintage 2025 · 2020–2025). Income migration comes from IRS Statistics of Income (IRS SOI 2022–2023 (2-yr lag)). Counties with fewer than 10,000 residents are not ranked. Data last loaded 2026-09-23.
Data as of 2026-09-23: sources and periods
- Population, growth and migration
- U.S. Census Bureau, Population Estimates Program: PEP Vintage 2025 · 2020–2025. census.gov/programs-surveys/popest
- Income migration (net AGI)
- Internal Revenue Service, Statistics of Income migration data: IRS SOI 2022–2023 (2-yr lag). irs.gov/statistics/soi-tax-stats-migration-data
How to read the table
- Population is the Census July 1 estimate of the latest vintage.
- Growth is the compound annual rate over 2020 to 2025.
- Net domestic and international migration are cumulative people over 2020 to 2025.
- IRS net AGI migration is adjusted gross income that moved in, less what moved out, for 2022 to 2023. A plus sign means a net inflow.
- Places with fewer than 10,000 residents are left out of the rankings.