County ZIP codes · New Jersey · FIPS 34023
Middlesex County, NJ ZIP Codes
Middlesex County, New Jersey has 51 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 42 residential and 9 for PO boxes or a single organization. 36 of the residential ones lie mainly in Middlesex County and 6 mainly in a neighboring county; 8 cross the county line. Median household income ranges from $64,491 in 08861 (Perth Amboy) to $176,983 in 08540 (Princeton) (Census Bureau, ACS 2020-2024).
- ACS2020-24
- Census2020
Where are the ZIP codes of Middlesex County?
Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).
How different are its ZIP codes?
The middle half of its ranked ZIP codes (1,000+ people living in households) report median household incomes between $101,670 and $133,209.
They carry 40 postal town names.
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).
All 42 residential ZIP codes in Middlesex County
36 ZIP codes lie mainly in Middlesex County; 6 more reach into it from a neighboring county and follow the first table.
| In this county | ||||||
|---|---|---|---|---|---|---|
| 08854 | Piscataway | 61,088 | 3,227 | $128k | $450k | 100% |
| 08861 | Perth Amboy | 59,351 | 11,640 | $65k | $371k | 100% |
| 08901 | New Brunswick | 57,263 | 9,137 | $66k | $354k | 100% |
| 08831 | Monroe Township | 55,658 | 1,085 | $109k | $517k | 100% |
| 08816 | East Brunswick | 49,360 | 2,439 | $144k | $523k | 100% |
| 08817 | Edison | 49,020 | 4,618 | $111k | $431k | 100% |
| 08902 | North Brunswick | 43,932 | 3,336 | $121k | $434k | 100% |
| 08857 | Old Bridge | 40,891 | 1,700 | $109k | $487k | 100% |
| 08820 | Edison | 39,978 | 3,833 | $171k | $630k | 100% |
| 07747 | Matawan | 32,330 | 2,528 | $124k | $486k | 55% |
| 07008 | Carteret | 25,526 | 5,805 | $97k | $406k | 100% |
| 08859 | Parlin | 25,448 | 5,351 | $100k | $446k | 100% |
| 07080 | South Plainfield | 24,411 | 2,969 | $130k | $471k | 100% |
| 08879 | South Amboy | 23,556 | 3,326 | $93k | $390k | 100% |
| 08536 | Plainsboro | 20,817 | 2,764 | $138k | $704k | 100% |
| 07095 | Woodbridge | 20,756 | 4,504 | $105k | $390k | 100% |
| 08872 | Sayreville | 20,204 | 2,136 | $98k | $447k | 100% |
| 08830 | Iselin | 19,551 | 6,183 | $110k | $427k | 100% |
| 08837 | Edison | 19,437 | 2,128 | $103k | $438k | 100% |
| 07067 | Colonia | 18,587 | 4,613 | $123k | $493k | 100% |
| 08840 | Metuchen | 18,206 | 5,675 | $147k | $560k | 100% |
| 08852 | Monmouth Junction | 18,062 | 1,355 | $133k | $523k | 100% |
| 07001 | Avenel | 17,121 | 4,586 | $102k | $401k | 100% |
| 08882 | South River | 16,124 | 5,759 | $96k | $405k | 100% |
| 08904 | Highland Park | 15,121 | 8,304 | $105k | $472k | 100% |
| 08846 | Middlesex | 14,645 | 4,199 | $105k | $446k | 100% |
| 08824 | Kendall Park | 13,366 | 3,083 | $175k | $628k | 100% |
| 08512 | Cranbury | 12,928 | 567 | $119k | $659k | 93% |
| 08863 | Fords | 12,771 | 7,460 | $116k | $438k | 100% |
| 08850 | Milltown | 8,538 | 3,704 | $142k | $471k | 100% |
| 08884 | Spotswood | 8,187 | 3,544 | $105k | $370k | 100% |
| 08810 | Dayton | 7,952 | 1,442 | $152k | $497k | 100% |
| 07064 | Port Reading | 3,481 | 2,639 | $134k | $435k | 100% |
| 07077 | Sewaren | 3,248 | 2,106 | $109k | $429k | 100% |
| 08828 | Helmetta | 2,459 | 2,970 | $99k | $355k | 100% |
| 08832 | Keasbey | 2,252 | 1,036 | – | $279k | 100% |
Partly in Middlesex County
| In this county | ||||||
|---|---|---|---|---|---|---|
| 08812 | Dunellen | 14,224 | 2,801 | $118k | $443k | 21% |
| 07735 | Keyport | 19,159 | 3,946 | $98k | $406k | 16% |
| 07721 | Cliffwood | 4,277 | 4,690 | $123k | $425k | 11% |
| 08540 | Princeton | 50,388 | 974 | $177k | $768k | 11% |
| 08528 | Kingston | 321 | 340 | – | $234k | 5% |
| 07726 | Englishtown | 44,764 | 1,353 | $149k | $647k | 1% |
Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).
Which ZIP codes cross the county line?
8 ZIP codes of Middlesex County extend into another county. A ZIP code follows mail routes, not county borders.
| ZIP | In Middlesex | Elsewhere |
|---|---|---|
| 08540 | 11% | Mercer County 63%; Somerset County 26% |
| 07726 | 1% | Monmouth County 99% |
| 07747 | 55% | Monmouth County 45% |
| 07735 | 16% | Monmouth County 84% |
| 08812 | 21% | Somerset County 78%; Union County 1% |
| 08512 | 93% | Mercer County 7% |
| 07721 | 11% | Monmouth County 89% |
| 08528 | 5% | Somerset County 95% |
Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).
PO Box and single-organization ZIP codes
Source: GeoNames postal codes (CC BY 4.0).
Which first three digits do Middlesex County's ZIP codes use?
The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Middlesex County's ZIP codes use 5 prefixes: 070, 077, 085, 088 and 089.
| Prefix | Sectional center | Here | All codes |
|---|---|---|---|
| 070 | Dv Daniels, NJ (SCF 070) | 7 | 88 |
| 077 | Trenton, NJ (SCF 085) | 4 | 48 |
| 085 | Trenton, NJ (SCF 085) | 4 | 37 |
| 088 | Dv Daniels, NJ (SCF 070) | 29 | 67 |
| 089 | Dv Daniels, NJ (SCF 070) | 7 | 7 |
Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.