ZIP Code 08831: Monroe Township and Jamesburg, New Jersey Explained

Two Towns, One ZIP Code

Two municipalities share one ZIP code here: Monroe Township and Jamesburg Borough, which sits inside Monroe’s boundaries but is governed separately. Monroe Township’s school registration page states plainly that grade K through 8 students living in Jamesburg attend Jamesburg’s own public schools, while Jamesburg’s high-schoolers are sent to Monroe Township High School – a detail that only makes sense if the two places are administratively separate, not neighborhoods of one town. If mail, a form, or a listing shows “Jamesburg, NJ 08831,” that’s not a typo or an old name for part of Monroe: it’s the correct name of a different municipality sharing the ZIP.

The practical upshot: property taxes, municipal services, and local elections run through whichever town your address sits in, even though both towns’ addresses carry the same five-digit code.

Is 08831 Jamesburg or Monroe Township?Both, depending on the property. The two are separate municipalities that share one ZIP code, with Monroe Township surrounding the much smaller Jamesburg. Check the municipality name on the deed or tax bill, not the ZIP, to know which one applies.

Who Makes Up 55,123 Residents

The 52.7 median age isn’t evenly spread. Monroe Township’s own list of local age-restricted communities names roughly a dozen developments – Rossmoor, Clearbrook, Concordia, Regency at Monroe, Renaissance at Monroe, Encore, Stonebridge, Greenbriar at Whittingham, and The Ponds among them – clustered mainly in the township’s Prospect Plains and Half Acre sections. Clearbrook alone, built out between 1972 and 1993, holds 2,026 homes behind its gates, with two clubhouses and a 9-hole golf course; a household moving into one of these communities is buying into a fundamentally different demographic mix than a household on a standard suburban street elsewhere in the ZIP.

That concentration is also why “median age 52.7” is a misleading number for a family house-hunter to anchor on: it blends a large retiree population with the township’s separate stock of standard single-family neighborhoods, which skew younger. The Census breakdown for the ZIP also shows a White plurality (62.8%) and an Asian population (24.2%) well above both the state and national averages, with Hispanic or Latino residents at 8.5%.

Are there age-restricted (55+) communities in this ZIP?Yes, roughly a dozen, concentrated in Monroe Township’s western and southern sections, ranging from a few hundred to over 2,000 homes each. None are in Jamesburg Borough.

What Homes Here Cost, and Why the Figures Disagree

The three numbers don’t disagree by accident. The Census figure is what owners say their home is worth, averaged across a five-year survey window that already lags today’s market. Zillow’s number is a modeled estimate for the entire township, which pulls in higher-value non-ZIP neighborhoods. Redfin’s is the only one built from actual closed sales inside 08831 itself, in a single recent month, and single-month medians swing with whatever mix of homes happened to sell, from starter condos in the 55+ communities to multi-acre single-family lots.

Why does the median home value figure differ between sites?Because each figure measures something different: owner-estimated value (Census), an algorithmic index for the whole township (Zillow), or actual closed-sale prices for the ZIP in one recent month (Redfin). None is wrong; they’re not measuring the same thing.

Which School District Your Address Falls Under

Every Jamesburg child attends Jamesburg’s own elementary and middle schools, then moves into Monroe Township High School under a sending/receiving agreement between the two districts, confirmed directly by Monroe Township’s registration instructions, which route Jamesburg high-school registrations to the Jamesburg Board of Education rather than to Monroe’s central office. Every Monroe Township child, by contrast, stays inside the Monroe Township School District from kindergarten through twelfth grade. There is no street-by-street boundary to check within Monroe Township itself: the split runs along the municipal line.

Which school district will my kids attend?If your address is in Jamesburg Borough, elementary and middle school run through Jamesburg Public Schools and high school runs through Monroe Township High School. If your address is in Monroe Township, all twelve grades run through the Monroe Township School District.

Why the Commute Runs Long

Rail service doesn’t reach either municipality directly: neither Monroe Township nor Jamesburg has its own NJ Transit station. The nearest Northeast Corridor Line stops, Metuchen, New Brunswick, and Princeton Junction, all sit outside the ZIP, which is why NJ Transit’s own Monmouth Ocean Middlesex project page lists a proposed Jamesburg stop as a still-unbuilt future addition, not a current one. Anyone commuting by rail today is driving to a station first.

What the Landfill and the Flood Maps Say

The landfill sits on Matchaponix Avenue and operated from the mid-1950s until 1978, first under Monroe Township itself and later under Browning-Ferris Industries. EPA placed it on the National Priorities List in September 1983 after leachate reached Lani Street; by 1993 the state had accepted the cap and monitoring system as protective and closed the active-cleanup phase, and EPA formally removed the site from the Superfund list in February 1994. The file isn’t purely historical: in August and September 2020, residents of the nearby Inwood Estates neighborhood reported chemical odors, and BFI stopped discharging collected leachate into the sanitary sewer on September 23, 2020, switching to off-site trucking days later.

Is there anything environmental I should know about before buying here?The closed Monroe Township Landfill on Matchaponix Avenue is a delisted, monitored Superfund site with an active cap-maintenance and leachate-collection program; a 2020 odor complaint near the site led to a change in how leachate is handled. It’s not an active hazard, but it is an ongoing maintenance site.

Who 08831 Suits, and Who Should Look Elsewhere

08831 fits retirees and near-retirees well: the age-restricted inventory is large, established, and amenity-heavy, and Redfin’s March 2026 figures show a ZIP where homes still take an average of 95 days to sell, not a frantic market. It fits buyers who don’t need direct-rail commuting into New York, since that infrastructure doesn’t exist here yet. It suits budget buyers less well if they anchor on the higher of the three home-value figures in the table above rather than the ZIP’s closed-sale median. And it suits anyone weighing school options only after they’ve confirmed which of the two municipalities their target address sits in, since that single fact, not the ZIP code, decides the school pipeline.