Real Estate Law · Allegheny County
Allegheny County Spot Reassessment After a Sale: Why Your Property Taxes Can Increase
Allegheny County property taxes are based on assessments tied to the county’s 2012 base year. Many homeowners therefore pay taxes based on property values from more than a decade ago. But when a property sells, that protection may disappear.
A sale can trigger what is commonly called a “spot reassessment.” The county reviews the property and may adjust the assessed value based on the purchase price or current market conditions. For buyers who assumed their taxes would match the seller’s tax bill, the result can be an unexpected increase.
A purchase price that significantly exceeds the current assessed value can attract the county’s attention. When a reassessment follows the sale, property taxes may rise to reflect the new valuation.
Call 412-351-4422 or schedule a consultation before completing a real estate transaction or recording a deed.
How the 2012 Base Year Affects Property Taxes
Allegheny County last conducted a countywide reassessment in 2012. Under Pennsylvania’s base year system, assessed values remain tied to that year until another countywide reassessment occurs.
This means many long-time homeowners continue paying property taxes based on 2012 values even though market prices have risen substantially since then.
The system benefits owners who have held property for many years. But the moment a property sells, the county may revisit the valuation.
What a Spot Reassessment Is
A spot reassessment occurs when the county reviews the assessed value of an individual property rather than reassessing the entire county. The most common trigger is a real estate sale.
When the purchase price is significantly higher than the assessed value, the county may treat that price as evidence that the property’s value has increased. The county can then adjust the assessed value accordingly.
Once reassessed, the property no longer reflects the historic 2012 value. The new owner’s tax bill may increase even though neighboring homes continue paying taxes based on older assessments.
The Role of the Common Level Ratio
Pennsylvania uses the Common Level Ratio to maintain uniform taxation in base-year counties. The ratio reflects the relationship between assessed values and current market prices.
Allegheny County’s 2026 Common Level Ratio is approximately 50.14 percent. In theory, this means assessed values average about half of market value across the county.
In an appeal, property owners may use the CLR to argue that the assessed value should reflect that relationship between assessments and market value.
Why Buyers Often See Higher Property Taxes
Buyers frequently assume that their property taxes will match the seller’s current tax bill. That assumption is often incorrect. The seller may be paying taxes based on a valuation that has not been updated since 2012.
After the sale, the county may review the property and reassess it based on the purchase price. When that occurs, the new tax bill reflects the updated assessed value rather than the historic base-year value.
Understanding this risk before closing allows buyers to evaluate the potential tax impact of a purchase.
Appealing a Reassessment
If the county reassesses the property after a sale, the new owner may still challenge the assessed value through the property assessment appeal process.
An appeal allows the property owner to present evidence of market value and challenge the county’s valuation methodology.
Appeal deadlines apply each year. Missing the filing deadline eliminates the ability to challenge the assessment for that tax year.
Related: This article explains how property sales can trigger reassessment in Allegheny County. For the appeal process and how to prepare for an assessment hearing, see our article on Allegheny County Property Assessment Appeals. For a deeper explanation of the 2012 base year and the Common Level Ratio, see Allegheny County Assessments: The 2012 Base Year and the CLR. For guidance on real estate transactions and title issues, see our Real Estate Transactions and Real Estate Issues pages.