In May 2026, the U.S. Census Bureau released Vintage 2025 sub-county population estimates for all incorporated places and minor civil divisions across the United States. These estimates, anchored to the April 1, 2020 decennial census, use annual administrative data on births, deaths, and migration to track population change at the municipal level through July 1, 2025. This brief summarizes key findings on population changes for municipalities in the eight counties of the Pittsburgh Metropolitan Statistical Area (MSA): Allegheny, Armstrong, Beaver, Butler, Fayette, Lawrence, Washington, and Westmoreland in southwestern Pennsylvania. For more information on the Census Bureau Population Estimates Program, including methodology documentation, data downloads, and interactive tools, visit: census.gov/programs-surveys/popest.
Relationship to county-level estimates. The Vintage 2025 sub-county estimates released in May 2026 are the final and most granular release in the Census Bureau's annual population estimates cycle. County-level estimates, including full components of change (births, deaths, domestic migration, and international migration), were published first, in March 2026. UCSUR published a companion data brief covering county-level and MSA-level population estimates on March 26, 2026 (2025 Census Population Estimates for the Pittsburgh Region). Sub-county estimates do not independently measure migration or natural change at the municipal level; instead, they distribute the already-published county totals down to individual places.
How sub-county estimates are produced. The Census Bureau uses the Distributive Housing Unit Method to allocate each county's household population to its constituent municipalities. The process begins with annual housing unit estimates for each place, derived from building permit data and administrative sources. Those counts are multiplied by the household population per housing unit ratio from the 2020 Census to produce an uncontrolled estimate for each place. The uncontrolled estimates are then scaled so that they sum to the published county total. Group quarters population (dormitories, prisons, nursing facilities) is estimated separately and added to yield the final resident population figure.
Key limitations. Several limitations affect the reliability of sub-county estimates. Because municipal estimates are controlled to county totals, any error in a county estimate propagates to all its municipalities. The housing unit method means that places with minimal new construction receive estimates driven primarily by county-level trends, not direct observation of movement in or out. Small municipalities are highly sensitive to minor revisions in housing unit counts. Additionally, with each new vintage, the full time series is revised back to 2020; figures in this brief (Vintage 2025) will differ from those in the prior Vintage 2024 brief and should not be directly compared to them. The sub-county file covers incorporated places and minor civil divisions but excludes unincorporated areas.
This data brief was prepared by Christopher Briem at the University of Pittsburgh's University Center for Social and Urban Research (UCSUR). He can be contacted at cbriem@pitt.edu or by phone at (412) 624-3791.
The Pittsburgh MSA encompasses 485 municipalities across its eight counties. These range from the City of Pittsburgh, with a 2025 estimated population of approximately 308,000, to dozens of small boroughs with fewer than 500 residents.
As of July 1, 2025, the Pittsburgh MSA had a total population of 2,421,992, ranking it the 28th largest MSA in the nation. Over the five years since the 2020 Census, the region has lost an estimated 34,924 residents, a cumulative decline of 1.42%. Notably, the region was one of only four of the 40 largest metro areas in the country to record an outright population loss between 2024 and 2025, alongside Los Angeles, San Diego, and Miami. The Pittsburgh region's trajectory reflects the compounding effects of the country's most severe rate of natural population decline among large metros, only partially offset by migration. The Pittsburgh region receives among the lowest rates of international in-migration of any large metropolitan area nationally, meaning that immigration provides less of a demographic buffer here than in most peer metros, compounding the impact of the region’s exceptionally high rate of natural population decline.
The table below shows the previously released cumulative five-year population change across the eight MSA counties. Butler and Washington counties remain the only counties with net population gains since 2020. The remaining six counties all declined, with Armstrong and Fayette posting the steepest percentage losses. Allegheny County, home to more than half the region's population, accounts for the largest absolute loss.
| County | 2020 Base | 2025 Est. | 5-Yr Change | 5-Yr % | 2024–25 Chg. | 2024–25 % |
|---|---|---|---|---|---|---|
| Allegheny | 1,250,581 | 1,225,035 | −25,546 | −2.04% | −2,139 | −0.17% |
| Armstrong | 65,572 | 63,698 | −1,874 | −2.86% | −57 | −0.09% |
| Beaver | 168,224 | 166,032 | −2,192 | −1.30% | +263 | +0.2% |
| Butler | 193,716 | 200,169 | +6,453 | +3.3% | +869 | +0.4% |
| Fayette | 128,820 | 123,021 | −5,799 | −4.50% | −938 | −0.76% |
| Lawrence | 86,065 | 83,911 | −2,154 | −2.50% | −176 | −0.21% |
| Washington | 209,331 | 210,802 | +1,471 | +0.7% | +167 | +0.1% |
| Westmoreland | 354,607 | 349,324 | −5,283 | −1.49% | −1,149 | −0.33% |
| Pittsburgh MSA Total | 2,456,916 | 2,421,992 | −34,924 | −1.42% | −3,160 | −0.13% |
The chart below summarizes how municipalities of the Pittsburgh MSA are distributed across six population change categories based on cumulative change between April 1, 2020 (the reference date for the 2020 decennial census), and July 1, 2025. Roughly 11% of municipalities registered any net growth over the five-year period, and just 4 municipalities fell into the significant decline category (losses exceeding 6%).
The largest bin, moderate decline (−6% to −2%) at 344 municipalities (71%), represents the broad stratum of communities losing population slowly but persistently. Many of these places are not in acute crisis by any single-year measure, but the cumulative weight of multi-decade decline has eroded fiscal capacity and service delivery. The significant decline bin (only 4 municipalities, those losing more than 6%) is disproportionately composed of older industrial communities in the river valleys of Allegheny, Westmoreland, Fayette, and Lawrence counties.
Among more than 2,500 incorporated places in Pennsylvania, the City of Pittsburgh recorded the largest cumulative numeric population gain in the state over the full 2020–2025 period, adding an estimated 4,578 residents (+1.5%) to reach approximately 307,632. This marks a significant shift for the city which had previously experienced at least 70 years of continuous population losses, and a notable outlier against the broader regional pattern of decline.
Outside the City of Pittsburgh, population growth continued to concentrate in Butler and Washington counties along the I-79 corridor. Butler County as a whole grew by +6,453 residents (+3.33%) over the five-year period, the only county in the MSA with sustained growth.
Ranked by total residents gained. Shows which municipalities added the most people in absolute terms.
| Municipality | County | 2020 Est. | 2025 Est. | Numeric Chg. | % Chg. |
|---|---|---|---|---|---|
| Pittsburgh city | Allegheny | 303,054 | 307,632 | +4,578 | +1.5% |
| Cranberry township | Butler | 33,065 | 35,244 | +2,179 | +6.6% |
| Jackson township | Butler | 4,889 | 6,585 | +1,696 | +34.7% |
| Slippery Rock township | Butler | 6,697 | 8,349 | +1,652 | +24.7% |
| North Strabane township | Washington | 15,842 | 17,433 | +1,591 | +10.0% |
| Findlay township | Allegheny | 6,373 | 7,541 | +1,168 | +18.3% |
| Adams township | Butler | 14,842 | 15,927 | +1,085 | +7.3% |
| Lancaster township | Butler | 2,744 | 3,734 | +990 | +36.1% |
| Pine township | Allegheny | 14,700 | 15,475 | +775 | +5.3% |
| Middlesex township | Butler | 6,827 | 7,513 | +686 | +10.1% |
| Municipality | County | 2020 Est. | 2025 Est. | Numeric Chg. | % Chg. |
|---|---|---|---|---|---|
| Lancaster township | Butler | 2,744 | 3,734 | +990 | +36.1% |
| Jackson township | Butler | 4,889 | 6,585 | +1,696 | +34.7% |
| Valencia borough | Butler | 542 | 681 | +139 | +25.6% |
| Slippery Rock township | Butler | 6,697 | 8,349 | +1,652 | +24.7% |
| Connoquenessing borough | Butler | 675 | 809 | +134 | +19.9% |
| Findlay township | Allegheny | 6,373 | 7,541 | +1,168 | +18.3% |
| Slippery Rock borough | Butler | 3,186 | 3,551 | +365 | +11.5% |
| Middlesex township | Butler | 6,827 | 7,513 | +686 | +10.1% |
| North Strabane township | Washington | 15,842 | 17,433 | +1,591 | +10.0% |
| Forward township | Butler | 3,154 | 3,412 | +258 | +8.2% |
Across the region, roughly 71% of municipalities experienced moderate decline (−6% to −2%), while an additional 17% showed low decline (−2% to 0%) between April 2020 and July 2025, reflecting the continued accumulation of small annual losses. The largest absolute declines remain concentrated in older industrial boroughs and cities along the Monongahela, Allegheny, and Ohio river valleys, where the combined forces of natural population decline, limited housing investment, and decades of out-migration continue to reduce populations. In several cases, notably California borough in Washington County, Connellsville, Uniontown, and South Union Township in Fayette County, the five-year cumulative loss now exceeds 5%.
In Fayette County, the largest percentage losses occurred in Connellsville and Uniontown, both now below their already-reduced 2020 levels by more than 5%. Armstrong County’s incorporated places continued shrinking in line with countywide trends, with no borough or city in the county recording growth over the five-year period.
| Municipality | County | 2020 Est. | 2025 Est. | Numeric Chg. | % Chg. |
|---|---|---|---|---|---|
| Penn Hills municipality | Allegheny | 41,018 | 39,452 | −1,566 | −3.8% |
| Bethel Park municipality | Allegheny | 33,597 | 32,074 | −1,523 | −4.5% |
| Mount Lebanon municipality | Allegheny | 34,068 | 32,552 | −1,516 | −4.5% |
| Ross township | Allegheny | 33,573 | 32,218 | −1,355 | −4.0% |
| Shaler township | Allegheny | 28,131 | 26,833 | −1,298 | −4.6% |
| McCandless township | Allegheny | 29,707 | 28,439 | −1,268 | −4.3% |
| Baldwin borough | Allegheny | 21,526 | 20,516 | −1,010 | −4.7% |
| Monroeville municipality | Allegheny | 28,642 | 27,685 | −957 | −3.3% |
| Plum borough | Allegheny | 27,147 | 26,225 | −922 | −3.4% |
| West Mifflin borough | Allegheny | 19,595 | 18,707 | −888 | −4.5% |
Ranked by percentage decline. Smaller communities with steeper proportional losses lead in this measure.
| Municipality | County | 2020 Est. | 2025 Est. | Numeric Chg. | % Chg. |
|---|---|---|---|---|---|
| California borough | Washington | 5,369 | 4,615 | −754 | −14.0% |
| Connellsville city | Fayette | 7,012 | 6,574 | −438 | −6.2% |
| Perryopolis borough | Fayette | 1,704 | 1,599 | −105 | −6.2% |
| Washington township | Fayette | 3,889 | 3,659 | −230 | −5.9% |
| Uniontown city | Fayette | 10,007 | 9,434 | −573 | −5.7% |
| South Union township | Fayette | 10,884 | 10,300 | −584 | −5.4% |
| Dormont borough | Allegheny | 8,229 | 7,816 | −413 | −5.0% |
| Ingram borough | Allegheny | 3,392 | 3,222 | −170 | −5.0% |
| Ben Avon borough | Allegheny | 1,920 | 1,824 | −96 | −5.0% |
| Tarentum borough | Allegheny | 4,344 | 4,127 | −217 | −5.0% |
The most consistent geographic pattern in the municipal data remains the Interstate 79 corridor from north Allegheny County through Butler County. Communities along this corridor, including Cranberry Township, Adams Township, and several smaller townships in southern Butler County, and Marshall Township in Allegheny County, have benefited from continued residential construction and proximity to employment centers along the North Shore and in the Strip District. Peters Township and Cecil Township in Washington County form a similar cluster along the I-79 southern extension.
Allegheny County accounts for the largest share of the region's absolute municipal population loss, concentrated in inner-ring suburbs and river communities east and south of the city. These communities share common characteristics: aging housing stock, limited undeveloped land for new residential construction, and populations skewed toward older age cohorts . Domestic out-migration from Allegheny County (−2,785 in 2024–2025 alone) reflects a longer-term pattern of households moving to the outer suburbs, particularly to locations in southwestern Butler and Washington counties.
Fayette, Lawrence, and Armstrong counties showed the most geographically widespread decline at the municipal level over the full 2020–2025 period. Fayette County's rate of natural decline, the highest in the MSA outside Allegheny County in absolute terms, compounds the effects of domestic out-migration in communities like Connellsville and Uniontown. Armstrong County showed no incorporated places recording population growth over five years. Lawrence County, newly added to the MSA definition in 2023, continued to decline across most of its municipalities, with New Castle city among the region's larger decliners.
Demographic change in the Pittsburgh region is defined by continuing geographic polarization. Over the most recent five years, the City of Pittsburgh and a small cluster of outer-ring communities along the I-79 corridor account for virtually all of the region's modest population gains. The remaining 90% of municipalities across the Pittsburgh region are losing population: most slowly, some rapidly.
Pittsburgh's status as Pennsylvania's top numeric gainer over the full 2020–2025 period is a meaningful signal of urban core resilience. At the same time, the region as a whole recorded an outright population loss in 2024–2025 (one of only four among the 40 largest metros nationally), a consequence of the country's most severe rate of natural population decline among large metropolitan areas, only partially offset by domestic and international migration gains.
