A common misconception in New York is that a recent sale — especially a high sale price — will automatically increase the buyer’s property taxes. Under New York law, that’s specifically not how the system is supposed to work. New York’s assessment framework is built around uniform valuation principles, not one-off reactions to an individual transaction. Understanding those principles — and the limits they impose on assessors — helps recognize when a change is appropriate and when it may cross the line into unlawful “selective reassessment.”
Equitable valuation, not one-off pricing
Assessments in New York are intended to reflect a uniform percentage of market value for all properties within the same assessing unit as of the taxable status and valuation dates for a given assessment roll. The highest courts in New York state have routinely decided that for commercial properties, an income approach to value is the preferred method of valuation. Assessors are required to set values using appraisal models that rely on income and expense patterns for commercial properties — not a single deed price.
In addition to not being the primary valuation tool, the conditions surrounding the sale can often render it irrelevant to the property’s true value. If the sale took place on a particular date and under particular conditions; it may include concessions, atypical motivation, or preexisting long-term leases that differ from the current market. The law requires the assessor to consider all conditions and whether that sale fits within broader market behavior.
Uniform percentage of value is the guardrail
New York law requires that all properties within the same assessing unit to be assessed at a uniform percentage of value. Some jurisdictions assess at (or aim for) full-market value; others apply a fractional ratio. Either way, the key is evenhandedness. If a town’s ratio is, for example, 60% of market value for a given class, assessments should be 60% across the board — not 100% for new buyers and 60% for long-time owners. This uniformity mandate is the backbone that prevents “welcome stranger” taxation. Any other treatment is a violation of the New York Constitution and the Equal Protection Clause.
What is selective reassessment (and why it’s a problem)?
Selective reassessment — often called “sales chasing”— occurs when an assessor updates the assessment of a newly sold property based primarily or solely on its sale price without making corresponding, systematic adjustments to comparable unsold properties. That practice undercuts uniformity because it imposes a different effective assessment ratio on the sold parcel than on its peers.
Selective reassessment can take several forms:
• Sale-price anchoring: The assessor moves the sold parcel to (or near) 100% of the deed price while leaving similar, unsold properties at lower effective ratios.
• One-off “corrections”: The office explains the change as “bringing it up to market,” but does not apply the same standard to like properties lacking a recent sale.
• Neighborhood-by-deed: A string of increases appears only on parcels that transferred, with no documented, model-based revaluation applied to the rest of the inventory.
These approaches erode equity and violate the requirement of uniform percentage within a class.
When assessment changes can be legitimate
Not every assessment change is improper. A post-transfer increase (or decrease) can be permissible when it reflects the same rules that apply to everyone. Common legitimate bases include:
• Physical change to the property as of the taxable status date (e.g., additions, demolition).
• Jurisdiction-wide or class-wide revaluation supported by a documented mass appraisal model and applied consistently to similarly situated parcels.
• Change in use that is legally relevant (e.g., conversion to a different property class with different valuation parameters).
In each of these scenarios, the touchstone remains the same: the assessor’s action must be evenhanded and consistent with the methodology used for other properties.
Practical implications for owners and buyers
Your purchase price does not automatically become your assessment or your tax base. An income approach is still the primary indication of market value as that is the same methodology applied equitably to similarly situated properties.
In New York, a sale does not dictate a tax increase for the “new guy.” The law’s uniformity requirement protects owners from being singled out, and selective reassessment — changing one parcel because it sold while ignoring its peers — runs counter to that mandate. If your assessment jumped after a purchase and the change isn’t supported by a class-wide, documented methodology or a legitimate property-specific reason, you are in position to challenge the assessment and restore equity.
Brad Cronin, Esq., and Sean Cronin, Esq., are partners at Cronin & Cronin Law Firm, PLLC, Mineola, N.Y.