Guide · Sources reviewed September 20, 2026
Can filing a tax grievance raise your assessment?
No. ARC says it will lower your assessment or leave it unchanged. Your bill can still change for other reasons, and a reduction doesn’t guarantee savings.
Nassau County states: “The Assessment Review Commission will never increase the assessment.” See the County’s appeal instructions and its assessment FAQ.
Common questions
Can filing a tax grievance raise my Nassau County assessment?
No. Nassau County states that the Assessment Review Commission will never increase the assessment. The County’s FAQ says the Commission will either reduce your assessment or leave it unchanged.
The County’s position appears in two places: its appeal instructions and its assessment FAQ. In other words, the downside of an ARC review is that nothing changes. Read the County’s own pages rather than relying on this summary, and confirm them for the year you are filing.
Can a SCAR hearing officer raise my assessment?
No. Nassau County states that the court-appointed referee in a Small Claims Assessment Review may order the Department to lower your assessment but cannot order it raised.
The same protection applies if you go further than ARC. See the County’s SCAR page, and our SCAR guide for who is eligible and the deadlines involved.
Does it cost anything to file an appeal with ARC?
Nassau County states that there is no fee to file with ARC, and that you are not required to use an attorney.
A SCAR petition is a separate step with its own $30 filing fee. If you hire a representative for either step, that is a commercial arrangement between you and them. Read the agreement, including how the fee is calculated and when it is owed. Good Grieves charges a flat $200 service fee with no percentage of your tax savings.
Will a lower assessment definitely lower my tax bill?
Not automatically. A tax bill depends on tax rates as well as assessed value, and Nassau County notes that school districts, towns and the County raise tax rates as needed. A reduction changes your share of the levy rather than setting your bill on its own. Savings are not guaranteed.
The County is blunt about the rate side: “The school districts, towns and the County raise tax rates as needed.” A reduction changes your share of what the districts collect; it does not cap what they collect. That is why no honest service can promise a dollar figure in advance, and why our calculator is labeled as a hypothetical illustration rather than a quote.
The real costs of filing
The risk is not a higher assessment. It is more ordinary than that:
- Your time. Gathering records and reviewing nearby sales takes an evening or two.
- Duplicate filings. If a representative or a condominium board already files for you, a second application creates conflicts. Check your existing agreement first.
- Missing the window. Each year’s assessment is appealed on its own schedule. See the filing-window guide.
Start with the record, not the rumor
Look up your property to see the available County figures for your home, then read how the process works end to end. This page is general information, not legal or tax advice, and using our tools does not file an appeal for you.
Keep reading
Is it worth grieving your taxes?
For most homes, yes. It’s free, it can’t raise your assessment, and most homes that file win something.
How to grieve your taxes in Nassau County
Check your assessment, file free with ARC by March 1, then go to SCAR if ARC doesn’t cut it.
See how it applies to a real home
Look up any County record alongside what you’ve learned.
Check a property