Census-designated place · New Jersey
Monmouth Junction, New Jersey
Monmouth Junction, census-designated place, in Middlesex County, New Jersey. Monmouth Junction had 9,141 people in the ACS 2020-2024 5-year estimates (±1,016). GEOID 3447190.
Residents, 2020-2024
9,141
±1,016 (90% margin)
2020 Census count: 8,895
Median household income
$133,585
±$27,111 (90% margin)
New Jersey: $103,556
Median home value
$552,900
±$75,805 (90% margin)
New Jersey: $454,400
Median gross rent
$1,935
±$127 (90% margin)
New Jersey: $1,720
Where is Monmouth Junction and what county is it in?
Monmouth Junction is a census-designated place: an unincorporated community the Census Bureau draws for counting, with no city government of its own, in Middlesex County, New Jersey. It covers 4.4 square miles of land, 2,030 residents per square mile in 2020.
Monmouth Junction is in the New York-Newark-Jersey City, NY-NJ metropolitan statistical area, which takes in 22 counties (Census Bureau delineation, July 2023).
Monmouth Junction lies entirely within South Brunswick Township, a township with its own local government (2020 census blocks).
Source: 2024 Gazetteer and 2020 place-by-county files, U.S. Census Bureau · Census reference files
How many people live in Monmouth Junction, and is it growing?
The 2020-2024 American Community Survey puts Monmouth Junction's population at 9,141 (±1,016). The 2020 Census counted 8,895 residents.
The Census Bureau publishes yearly population estimates for incorporated places only; Monmouth Junction is a census-designated place, so its figures come from the ACS and the 2020 Census.
| Measure | Monmouth Junction | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| Total population | 9,141 ±1,016 | 871,290 | +6,235 |
| Households | 3,478 ±378 | 307,782 | +2,566 |
| Average household size | 2.63 ±0.15 | 2.75 | −0.55 |
| Housing units | 3,536 ±372 | 317,979 | +2,624 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); Census PEP Vintage 2025 (SUB-EST2025, CO-EST2025); 2020 Census P.L. 94-171 · Check it at data.census.gov
Who lives in Monmouth Junction?
The median resident of Monmouth Junction is 39.9 years old; 21.5% are under 18 and 12.9% are 65 or older. The largest group is non-Hispanic Asian residents at 59.9%, then non-Hispanic white residents at 26.9%. 48.3% of residents were born outside the United States.
| Measure | Monmouth Junction | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| Median age | 39.9 ±2.7 | 39.5 | no clear change |
| Under 18 years | 21.5% ±3.4 pts | 21.5% | – |
| 65 years and over | 12.9% ±3.3 pts | 16.1% | – |
| Male | 46.4% ±3.6 pts | 49.7% | – |
| Hispanic or Latino (any race) | 4.8% ±3.9 pts | 23.6% | – |
| White alone, not Hispanic | 26.9% ±6.5 pts | 37.5% | −13.6 pts |
| Black or African American alone, not Hispanic | 4.7% ±3.0 pts | 9.7% | – |
| Asian alone, not Hispanic | 59.9% ±7.1 pts | 25.4% | +14.5 pts |
| American Indian and Alaska Native alone, not Hispanic | 0.0% ±0.5 pts | 0.1% | – |
| Native Hawaiian and Other Pacific Islander alone, not Hispanic | 0.0% ±0.5 pts | 0.0% | – |
| Two or more races, not Hispanic | 3.0% ±1.9 pts | 2.9% | – |
| Some other race alone, not Hispanic | 0.7% ±0.7 pts | 0.8% | – |
| Born outside the United States | 48.3% ±5.2 pts | 35.4% | no clear change |
| Speak a language other than English at home (age 5+) | 57.1% ±6.7 pts | 47.4% | – |
| Civilian veterans (age 18+) | 0.9% ±0.7 pts | 3.0% | – |
| With a disability | 4.9% ±2.2 pts | 10.0% | – |
| No health insurance coverage | 2.0% ±1.6 pts | 7.2% | – |
| High school graduate or higher (age 25+) | 96.0% ±2.0 pts | 89.2% | – |
| Bachelor's degree or higher (age 25+) | 75.8% ±5.0 pts | 45.6% | no clear change |
| Graduate or professional degree (age 25+) | 39.4% ±6.1 pts | 19.4% | – |
| Lived in the same house a year earlier | 91.5% ±3.5 pts | 89.6% | – |
| Moved from another state in the past year | 1.3% ±1.3 pts | 2.0% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profiles DP02, DP05) · Check it at data.census.gov
What do households in Monmouth Junction earn?
Half of Monmouth Junction's 3,478 households earn less than $133,585 a year (±$27,111), against $111,549 in Middlesex County and $103,556 in New Jersey. In 2015-2019 the median was $185,219 in 2024 dollars, so it fell by $51,634 after inflation.
| Measure | Monmouth Junction | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| Median household income | $133,585 ±$27,111 | $111,549 | −$51,634 |
| Mean household income | $181,065 ±$22,783 | $142,003 | – |
| Per capita income | $69,027 ±$7,928 | $50,601 | no clear change |
| People below the poverty line | 6.2% ±4.2 pts | 8.6% | – |
| Children under 18 below the poverty line | 6.6% ±5.2 pts | 10.6% | – |
| Households receiving SNAP | 1.9% ±1.6 pts | 7.9% | – |
| Households with a computer | 98.7% ±2.1 pts | 96.5% | – |
| Households with a broadband subscription | 97.5% ±2.4 pts | 94.3% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What does housing cost in Monmouth Junction?
Owners occupy 64.1% of Monmouth Junction's occupied homes and renters 35.9%. The median owner-occupied home is valued at $552,900 by its owner (±$75,805). The median renter pays $1,935 a month including utilities, and 24.9% of renters pay 35% or more of their income on rent.
| Measure | Monmouth Junction | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| Median home value (owner-occupied) | $552,900 ±$75,805 | $462,900 | no clear change |
| Median gross rent | $1,935 ±$127 | $1,871 | −$965 |
| Renters paying 35% or more of income on rent | 24.9% ±10.5 pts | 38.8% | no clear change |
| Median monthly owner costs, with a mortgage | $3,297 ±$351 | $2,877 | – |
| Owner-occupied homes | 64.1% ±4.6 pts | 63.6% | −28.6 pts |
| Renter-occupied homes | 35.9% ±4.6 pts | 36.4% | – |
| Housing units | 3,536 ±372 | 317,979 | +2,624 |
| Homeowner vacancy rate | 0.0% ±1.9 pts | 0.4% | – |
| Rental vacancy rate | 0.0% ±3.5 pts | 2.4% | – |
| Single-family detached homes | 39.2% ±6.3 pts | 52.4% | – |
| Mobile homes | 0.0% ±1.3 pts | 0.8% | – |
| Built 2020 or later | 0.4% ±0.6 pts | 0.9% | – |
| Built 2010 to 2019 | 13.5% ±5.3 pts | 6.6% | – |
| Built 1939 or earlier | 2.8% ±1.9 pts | 10.4% | – |
| Households with no vehicle | 8.7% ±4.5 pts | 8.0% | – |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP04) · Check it at data.census.gov
How do people in Monmouth Junction work and get to work?
65.5% of Monmouth Junction's workers drive alone and 27.0% work from home. The average trip to work takes 35.0 minutes. The unemployment rate in 2020-2024 averaged 4.3%.
| Measure | Monmouth Junction | Middlesex County | Change since 2015-2019 |
|---|---|---|---|
| In the labor force (age 16+) | 76.5% ±4.4 pts | 67.2% | – |
| Unemployment rate | 4.3% ±1.7 pts | 6.7% | – |
| Drove alone to work | 65.5% ±5.0 pts | 61.3% | – |
| Carpooled | 3.4% ±2.5 pts | 8.1% | – |
| Public transportation | 2.9% ±1.8 pts | 5.9% | – |
| Walked | 0.4% ±0.7 pts | 2.9% | – |
| Worked from home | 27.0% ±5.1 pts | 18.1% | – |
| Mean travel time to work | 35.0 min ±3.9 | 31.2 min | no clear change |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) (Data Profile DP03) · Check it at data.census.gov
What census tracts are in Monmouth Junction?
1 census tract lies mostly in Monmouth Junction, and 4 more reach into it (2020 census blocks).
| Tract | Residents, 2020-2024 | Median household income |
|---|---|---|
| Tract 85.04Middlesex County | 7,853 | $133,315 |
| Tract 85.06Middlesex County | 4,284 | $167,860 |
| Tract 85.01Middlesex County | 4,837 | $112,460 |
| Tract 85.05Middlesex County | 4,593 | $159,494 |
| Tract 85.02Middlesex County | 6,116 | $231,983 |
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026); 2020 block assignment files (tract share = share of the tract's census blocks in Monmouth Junction) · Census block assignment files
How does Monmouth Junction compare with other places in New Jersey?
Monmouth Junction ranks 247th of 771 places in New Jersey with 1,000 or more residents and a reliable estimate, by median household income.
| Measure | Rank | Of |
|---|---|---|
| Population (ACS 2020-2024) | 318th | 787 |
| Residents per square mile | 416th | 787 |
| Median household income | 247th | 771 |
| Per capita income | 211th | 785 |
| Median home value | 234th | 777 |
| Median gross rent | 250th | 701 |
| Bachelor's degree or higher | 46th | 780 |
| Median age | 565th | 786 |
| Owner-occupied share | 593rd | 777 |
| Work from home | 109th | 695 |
| Travel time to work | 144th | 787 |
Monmouth Junction's figures with every place in New Jersey (CSV)
Every place in New Jersey, sortable · Compare Monmouth Junction with other places
Source: PlainCities ranks computed from the American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026) and PEP Vintage 2025 · How ranks are computed
How reliable are the figures for Monmouth Junction?
17 of the 57 figures for Monmouth Junction on this page carry a coefficient of variation over 40% and are marked with a ring: they come from a small sample, so read them as rough.
The American Community Survey samples about one household in eight over five years, so every figure is an estimate with a 90% margin of error (shown under each value). A ring marks an estimate whose coefficient of variation is over 40%. A change is called only when the gap between the two periods is larger than their combined 90% margin (the square root of the sum of the two squared margins), the Census Bureau's test. How to read a margin of error.
Source: American Community Survey 2020-2024 5-year estimates, U.S. Census Bureau (released January 2026): margins of error as published · ACS technical documentation
How these figures are made: methodology and release checks · reading a margin of error · every state · corrections
Not on this page: crime, weather and schools for Monmouth Junction are other agencies' records. Crime: the FBI's Crime Data Explorer · climate: NOAA's U.S. Climate Normals · schools: the National Center for Education Statistics' school search.