What a Property Tax Assessment Is
Every property has two key numbers:
- Market value: what your home would likely sell for.
- Assessed value: what your local government uses to calculate property taxes.
Your property tax bill then comes down to a simple formula:
Assessed Value × Tax Rate = Property Tax
If you have an inflated assessment, you're paying more than your fair share.
How Assessments Impact Your Bill
Take a single-family home in Westchester County, NY, assessed at $900,000. With an effective tax rate of about 2.3%, the annual property tax is roughly $20,700. If the real market value is closer to $800,000, that homeowner could be overpaying by more than $2,000 a year. Even small discrepancies compound over time.
How Assessors Estimate Property Value
Assessors use standardized models that rely on several inputs:
- Comparable sales: Prices of similar nearby properties
- Property details: Square footage, bedrooms, age, and condition
- Improvement records: Permits for additions or renovations
- Mass appraisal models: Automated systems estimating values in bulk
These systems are efficient, but imperfect. One bad data point, like an incorrect square footage or a misclassified upgrade, can push your assessment well above reality.
How Often Assessments Are Updated
Reassessment frequency varies by location. Here are some examples:
| County | Frequency |
|---|---|
| Middlesex, MA | Annual updates; major revaluations every few years |
| Westchester, NY | Varies by town—some yearly, others after long gaps |
| Fairfield, CT | Full revaluation required every five years |
If your property hasn't been reassessed in several years, its value may no longer reflect current market conditions.
Reviewing Your Assessment Record
Most counties now offer online databases. Search your property by address or parcel ID and confirm details like square footage, number of bedrooms and baths, year built, and lot size.
Spot something off? Take notes and gather proof like photos, floor plans, appraisals. Many successful appeals come down to correcting basic data errors.
How and When to Appeal
If your assessment seems high, you can file an appeal—a formal request for review (not a lawsuit). Deadlines vary by state:
| State | Deadline |
|---|---|
| Massachusetts | February 1, 2026 (Boston: February 2) |
| New York | May 26, 2026 (Nassau: March 1; Westchester: June 16) |
| Connecticut | February 20, 2026 (some towns extend to March 20) |
To strengthen your case, submit clear documentation: recent comparable sales, independent appraisals, or evidence of record errors. The clearer your data, the higher your odds.
Why It Pays to Understand Your Assessment
Even if you never appeal, knowing how your property is valued helps you check for fairness, anticipate and prepare for tax remittance, and track local market shifts.
Property taxes fund schools, roads, and public safety—but fairness depends on accuracy. A quick review each year ensures you're paying only what's due—nothing more.
Ready to Take Action?
Understanding your assessment is the first step. Actually appealing it requires research, documentation, and navigating local procedures—all while managing strict deadlines.
If you'd prefer to focus on your life while we handle the complexities, we'll prepare a complete appeal package tailored to your property and jurisdiction for a flat $50 fee. No percentage cuts, no hourly billing—just professional results.