Nassau & Suffolk County Property Tax Grievance Deadlines (2026): What Homeowners Need to Know
If you own a home on Long Island and feel like your property taxes are too high, you’re not alone. In many cases, homeowners may be able to challenge their property tax assessment through a property tax grievance — but deadlines matter.
Below are the key filing deadlines for both Nassau County and Suffolk County, plus what you should know before you wait too long.
2026 Property Tax Grievance Deadlines (Nassau & Suffolk)
Here are the current grievance deadlines to keep on your radar:
NASSAU COUNTY (2027/28)
Deadline: March 31, 2026
SUFFOLK COUNTY (2026/27)
Deadline: May 19, 2026
Filing Deadline: Contact Our Office
To file properly and on time, we recommend reaching out as early as possible so your case can be reviewed before the deadline.
Why Filing Early Matters (Even If the Deadline Feels Far Away)
Even though March and May may seem far away, starting early is one of the best ways to avoid missing your opportunity.
Filing early helps you:
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avoid last-minute stress and paperwork issues
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confirm whether your assessment looks too high
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gather supporting documentation if needed
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reduce the chance of filing errors
If your goal is to lower your property tax burden, the earlier you review your assessment, the better.
Nassau County Deadline: March 31, 2026 (2027/28)
For Nassau County homeowners, the deadline to file a property tax grievance is March 31, 2026, and it applies to the 2027/28 tax year.
A grievance is essentially a way to challenge the assessed value of your property — because when an assessment is too high, it can lead to an inflated tax bill.
Many Nassau homeowners file when:
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their assessment increased unexpectedly
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nearby comparable homes appear to be assessed lower
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their home’s market value doesn’t match the assessment
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they believe they’re paying more than they should
Suffolk County Deadline: May 19, 2026 (2026/27)
For Suffolk County homeowners, the grievance deadline is:
May 19, 2026 for the 2026/27 tax year.
The goal is similar: if your assessment does not reflect fair market value, filing a grievance may help reduce what you pay in property taxes.
Some common reasons Suffolk homeowners explore filing include:
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taxes rising year after year with no clear explanation
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similar homes nearby paying less
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a home purchase that triggered a reassessment
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a mismatch between assessed value and current market conditions
What Happens After You File? (Quick Timeline Overview)
A property tax grievance is not an instant process — it often takes time for the county to review and issue decisions.
In general, the process may look like this:
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assessment review
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grievance filing submission
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county evaluation
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decision and next steps
If you want a deeper breakdown, we also recommend reviewing our full guide on how long the grievance process typically takes.
Why Your Property Tax Bill Can Be High (Even If Your Home Didn’t Change)
One confusing part of property taxes is that your bill is influenced by more than just your home’s value.
Property tax totals can include:
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school tax rates
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town/county rates
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special district charges and local levies
This is one reason homeowners may see increases even when they haven’t made major improvements to their property.
FAQs: Nassau & Suffolk County Grievance Deadlines
What is the Nassau County property tax grievance deadline for 2026?
March 31, 2026 (for the 2027/28 tax year).
What is the Suffolk County property tax grievance deadline for 2026?
May 19, 2026 (for the 2026/27 tax year).
Do I have to contact the office to file?
Yes — to ensure your filing is handled properly and submitted on time, contact our office before the deadline.
How long does the grievance process take?
Timelines vary, but decisions often take months depending on county schedules and volume.
Does filing guarantee a tax reduction?
Not always — but if your assessment is truly higher than it should be, filing may improve your chances of a reduction.
Next Step: Contact Our Office Before the Filing Deadline
If you believe your Nassau or Suffolk County assessment may be too high, the best next step is to contact our office before the deadline.
Nassau County (2027/28): March 31, 2026
Suffolk County (2026/27): May 19, 2026
Getting started early gives you more time to review your options and avoid missing your chance to file.
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