Property Tax in Mercer County, New Jersey

Property Tax in Mercer County

A calculator and field guide for Trenton-area homeowners — and for anyone considering a move to Mercer County — including New Jersey's General Tax Rate per $100 of assessed value, the high effective rates that produce the nation's largest property tax bills, the substantial intra-county variation between municipalities, and the Senior Freeze (PTR) reimbursement program for income-qualified 65+ homeowners.

Mercer County, home to Trenton and 390k New Jerseyans, operates within New Jersey's notoriously high property tax system. NJ has the highest effective property tax rate in the United States (approximately 2.23% statewide), and 10 of the 26 US counties with average single-family bills exceeding $10,000 are in New Jersey. Within Mercer County, individual municipalities can vary substantially in rate — strategic municipality selection is critical for relocation buyers.

How the bill is built

New Jersey's calculation is municipality-driven. Step 1: Assessed Value. Most NJ municipalities assess at "true value" (~100% market) but some assess at lower percentages, with the Equalization Ratio bridging stated AV and market. Step 2: General Tax Rate. The municipality publishes a General Tax Rate per $100 of assessed value, combining county, municipal, and school district levies. For the Mercer County average, this is approximately $2.79 per $100 AV. Step 3: Effective Rate. NJ Treasury also publishes an Effective Tax Rate = General Tax Rate × Equalization Ratio. This is the most apples-to-apples figure for relocation comparisons. Mercer County's average effective rate is approximately 2.79%.

Intra-county variation is dramatic. Mercer County's average effective rate is 2.79%, but individual municipalities within the county can range from substantially lower (industrial-only or commercial-heavy boroughs) to substantially higher (older inner-ring suburbs with high school spending). Strategic municipality selection within the same general area can change a buyer's annual tax bill by $3,000-$10,000+ on similar-priced homes.

Senior Freeze (PTR) reimburses tax growth above a base year for income-qualified 65+ homeowners — income limit ~$163,050 for 2024 (one of the most generous senior programs in the country in income terms). The program reimburses the difference between current bill and the bill in your "base year" (typically the year you turned 65 or first qualified). Combined with the ANCHOR direct rebate program ($1,000-$1,750 for income-qualified homeowners), New Jersey retirees can offset substantial annual property tax even though the underlying rates remain the highest in the nation.

100% disabled veterans receive full exemption. Given NJ's very high underlying rates, this is among the most valuable property tax benefits in the United States. File Form V.S.S. with your municipal assessor with VA documentation. Surviving spouses retain the exemption under specific conditions.

Mercer County rate breakdown (avg general tax rate per $100 of assessed value, Trenton district)

Taxing entity	Rate
West Windsor-Plainsboro School District	1.8900
Mercer County (general)	0.6050
Township of West Windsor	0.2950
Combined total	2.7900

Data record updated April 27, 2026. This is an editorial update date, not a tax year or a guarantee that every figure has been independently verified.

Sources and scope: Check rates and parcel details with Mercer County Board of Taxation. Figures may refer to different source years; a county-seat rate does not apply to every address. How we use data and estimates.

Note: Mercer County is home to New Jersey's state capital (Trenton), Princeton University (founded 1746), and a substantial corporate and pharmaceutical office base in Princeton/Plainsboro/West Windsor (Bristol Myers Squibb, Johnson & Johnson, Bloomberg, NRG Energy). Princeton is one of the wealthiest small cities in the US; Trenton anchors significant state employment.

Note: New Jersey property tax is among the highest in the United States — Mercer's ~2.79% effective rate is roughly aligned with the NJ state median (~2.46%) but well above the national median (~1.02%). The Mercer school districts (West Windsor-Plainsboro, Princeton, Lawrence) are consistently among the highest-rated in NJ but also among the most expensive — driving substantial school-tax loads.

Note: NJ provides a categorical 100% disabled veteran property tax exemption (NJSA 54:4-3.30) — full exemption from real property tax on the principal residence, no income or value cap. Surviving spouses retain. NJ's ANCHOR property tax relief program provides up to $1,750 for income-tested homeowners; NJ Senior Freeze (PTR-1) reimburses 65+ homeowners for the increase in property tax over a base year.

Deductions, exemptions, and senior programs for 2026

New Jersey's underlying property tax rates are the highest in the nation, but the state offers several substantial relief programs — particularly for seniors and disabled veterans. Most are filed annually through different forms and agencies.

Senior Freeze (Property Tax Reimbursement)

The Senior Freeze ("PTR") reimburses property tax growth above a base year for income-qualified homeowners 65+ or disabled. Income limit is approximately $163,050 for 2024 — among the most generous senior program income limits in the country. The program reimburses the difference between current bill and your "base year" bill (typically the year you turned 65 or first qualified). You continue paying the full bill to your municipality but receive a state reimbursement check. File Form PTR-1 (first-time) or PTR-2 (subsequent years) with the New Jersey Division of Taxation.

ANCHOR (Affordable NJ Communities for Homeowners and Renters)

ANCHOR replaced the older Homestead Benefit program in 2022. Eligible homeowners receive a direct rebate: $1,500 for households earning under $150,000, $1,000 for households earning $150,000-$250,000. Senior homeowners (65+) receive an additional $250. ANCHOR is filed annually with the NJ Division of Taxation, typically with a fall deadline.

$250 Veteran and Senior Deductions

Honorably-discharged veterans (any rating, any age) receive a $250 annual deduction. Senior homeowners 65+ or disabled receive a separate $250 annual deduction. These are filed with your municipal tax assessor (form V.S.S.-Q for veterans, P.T.D. for seniors).

100% Disabled Veterans — Full Exemption

Veterans with 100% service-connected total/permanent disability receive full property tax exemption — among the most valuable property tax benefits in the United States given NJ's very high underlying rates. File Form V.S.S. with your municipal assessor with VA documentation. Surviving spouses retain the exemption under specific conditions.

Appealing your assessment

New Jersey's appeal deadline is April 1 in most counties (Monmouth has alternative timing under the Assessment Demonstration Program). Appeals are filed with the Mercer County Board of Taxation. NJ uses a 15% "common level range" rule — your assessment must be more than 15% higher than the county equalization ratio applied to your true market value to qualify for adjustment, providing a buffer that protects assessors from minor disputes. Strong appeals require comparable sales data within the prior 12 months. Tax appeal data shows 10-25% reductions are common when supported by quality comps.

Cities and towns in Mercer County

This guide lists 6 selected communities in or associated with Mercer County. It is not a complete municipal directory. Local taxing districts can differ between communities and individual addresses.

Data: US Census Bureau, 2020 Decennial Census. Populations rounded. Cities marked as "split" straddle a county border — the portion inside Mercer County is subject to Mercer County's tax rolls, while the portion outside is subject to the adjacent county's.

City or town	Type	Population (2020)
Hamilton Township	township	92,300
Trenton County seat	city	90,000
Ewing Township	township	36,900
Lawrence Township	township	33,700
Princeton	municipality	31,000
West Windsor	township	30,200

About city-level property tax rates: The rate breakdown and calculator on this page use a representative district around Trenton. Other cities in Mercer County may pay into different school districts, city rates, and special districts — so their combined rates can differ, sometimes substantially. Always verify the specific rates for your address with the Mercer County Board of Taxation before relying on any estimate.

Frequently asked questions

When are Mercer County property taxes due?

New Jersey property taxes are paid in quarterly installments: February 1, May 1, August 1, and November 1. Each municipality bills separately (NJ has no county-level billing). A 10-day grace period applies after each due date; late payments incur 8% interest on the first $1,500 of delinquency and 18% on amounts above.

Why are New Jersey property taxes so high?

New Jersey funds a substantial portion of public school costs through property tax rather than state income or sales tax. Combined with NJ's 564 separate municipalities (each maintaining its own government, police, and services), per-capita government costs are among the highest in the country — and property tax is the primary funding mechanism. School portion alone typically accounts for 50-65% of the total bill.

How can I qualify for Senior Freeze (PTR)?

You must be 65+ or disabled, have lived in NJ for at least the last 10 years, owned and lived in your current home for at least the last 3 years, and have household income under approximately $163,050 (2024). The program reimburses growth above your "base year" bill — you continue paying the full bill to your municipality and receive a state reimbursement check. File Form PTR-1 (first-time) or PTR-2 (subsequent years).

How do I appeal my assessment?

NJ's appeal deadline is April 1 in most counties (Monmouth has alternative timing under the Assessment Demonstration Program). File with the Mercer County Board of Taxation. NJ uses a 15% common level range rule — your assessment must be more than 15% higher than the county equalization ratio applied to your true market value to qualify for adjustment. Strong appeals require comparable sales data within the prior 12 months.

About Mercer County

Beyond the property tax — a few things you might not know about the place.

Weird fact

Albert Einstein’s home at 112 Mercer Street in Princeton — where he lived from 1936 until his death in 1955 — is now privately owned but bears a quiet historical marker. The Institute for Advanced Study, where Einstein was based, is on Olden Lane in Princeton; many Nobel laureates have worked there over the decades.

Hometown hero

Albert Einstein

Theoretical physicist, Nobel laureate (1921 Physics), and originator of the theory of general relativity. Moved to Princeton in 1933 to escape Nazi Germany; spent the rest of his life at the Institute for Advanced Study. Lived at 112 Mercer Street in Princeton until his death in 1955.

Biggest annual event

Battle of Trenton reenactment

Annual December 26 reenactment of George Washington’s 1776 crossing of the Delaware River and surprise attack on the Hessian garrison at Trenton — the celebrated turning point of the American Revolution. Held at Washington Crossing State Park; draws thousands.

Property Tax in Mercer County