NoteTownship figures are computed from Cook County Assessor and Board of Review open data on the dates listed under sources.
Property · New Trier Township · Cook County, Illinois

New Trier Township property tax appeal, Cook County

The median residential assessment in New Trier Township rose 32.4% at its 2025 reassessment, and of the appeals decided for tax year 2025, 28.4% of 13,597 at the Assessor changed the value and 50.5% of 14,722 at the Board of Review ended in a decrease. Appeals for tax year 2026 close 22 Jun 2026 at the Cook County Assessor — verified 25 Sep 2026.

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Appeal window

When New Trier Township can appeal

Where you appealOpensClosesDate we verified it
Cook County Assessor07 May 202622 Jun 202625 Sep 2026
Cook County Board of Review03 Aug 202601 Sep 202625 Sep 2026

From the Assessor’s and Board of Review’s published 2026 calendars. Dates can change; confirm with the office before filing.

Appeal outcomes

New Trier Township Board of Review and Assessor appeal results by year

Tax yearClosed Assessor appealsShare that changed the valueBoard of Review appealsShare decreased
20235,60520.9%9,36541.0%
20244,40614.0%8,25739.7%
202513,59728.4%14,72250.5%

Residential property classes (class 2, including condominium units). An Assessor appeal counts as changed when the Assessor’s record says the value changed; a Board of Review appeal counts as decreased when its result is “Decrease”. Shares aren’t printed from fewer than 30 appeals. Past outcomes don’t predict the result of any one appeal.

Reassessment

New Trier Township assessment increase, year on year

Assessment yearHomes assessed in both yearsMedian change
202421,341+0.0%
202521,332+32.4%
202621,367+0.0%

Assessor mailed values for class 2 properties in New Trier Township, compared with the same property’s value the year before. Cook County reassesses one of its three regions (North for this township) each year; in other years the median change is usually 0%. The latest year can be partial while notices are still being mailed. 21,412 residential parcels are in the township today.

Questions

New Trier Township appeals: common questions

When is the New Trier Township appeal deadline?

For tax year 2026, the Cook County Assessor window for New Trier Township opened 07 May 2026 and closes 22 Jun 2026. We last verified that date against the office’s published calendar on 25 Sep 2026; dates move, so confirm with the office before you file.

What are the odds an appeal in New Trier Township works?

In tax year 2025, 28.4% of the 13,597 closed residential appeals the Assessor decided for New Trier Township changed the assessed value, and 50.5% of the 14,722 residential appeals the Board of Review decided ended in a decrease. Those are township-wide rates from closed cases, not a prediction for any one property.

Should I appeal to the Assessor or the Board of Review in New Trier Township?

They are separate filings and the table above shows both. For 2025, New Trier Township sent 13,597 residential appeals to the Assessor and 14,722 to the Board of Review; 28.4% and 50.5% of them respectively moved the value. The Board of Review hears appeals after the Assessor has closed a township, so missing the first window does not end the year.

How much did assessments go up in New Trier Township?

At the 2025 reassessment the median residential assessment rose 32.4%, measured across the 21,332 class-2 properties the Assessor valued in both 2024 and 2025. That is the middle of the township, not your property: half the homes moved more.

What if the New Trier Township window has already closed?

Nothing on this page files an appeal for you, and a closed window can’t be reopened here. The figures above are per tax year, so the same tables tell you what the next year’s filing looks like; the free assessment check compares your home with near-identical homes nearby whenever you run it.

Every answer here restates a figure printed elsewhere on this page. Nothing is added that we haven’t measured and sourced.

What this page doesn’t cover
  • Your own property: use the free assessment check, which compares your home with near-identical homes nearby.
  • Tax bills, tax rates and exemptions.
  • Commercial property and appeals filed with the Property Tax Appeal Board.
  • Legal advice. CivicDelta doesn’t file appeals.

More: how a Cook County assessment appeal works · all 38 Cook County townships compared · everything we hold on property · how we compute these figures

Official sources and load dates
DatasetDataset IDLoaded
Assessor - Assessed Valuesuzyt-m5572026-09-28
Assessor - Appealsy282-6ig32026-09-28
Board of Review Appeal Decision History7pny-nedm2026-09-28
Assessor - Parcel Universe (Current Year Only)pabr-t5kh2026-09-13