Each county in the state of Pennsylvania will determine its own appeal deadline.  

The Allegheny County 2027 property tax assessment appeal deadline is September 1, 2026.

For a list of deadlines in other counties, click here.

Every county has a “base year” for tax assessment purposes. Property assessments are supposed to reflect a base year valuation.

The base year for Allegheny County is 2012. The CLR is a ratio which is intended to convert present day market values into base year assessed values.

The CLR in each county is adjusted annually based on sales data selected in their county.

The CLR is adjusted each year to take into account changes in property valuation.

In 2027, Allegheny County’s CLR will drop to 49.3%.  With the new CLR, a property with a 2027 market value of $1,000,000 should be assessed at $493,000.  In 2024, the same property would have been properly assessed at $541,000.

Taxing authorities will only seek a change in assessed value when it works to their benefit.  This typically occurs when a property is sold or a material improvement to the property is made.  In the context of a sale, the taxing authorities are essentially asking for a new assessment “snapshot” to be taken.  The applicable CLR which exists is used during this “snapshot”.  Without a tax appeal, the property’s assessed value can remain the same for many years. 

Yes, CLR applies to commercial, industrial, and income producing properties.

When it works to their benefit, taxing authorities chase new sales and seek an increase in assessed value. In doing so, the taxing authorities are essentially asking that a new “snapshot” of market value be taken and the current CLR applied to the purchase price of the property. 

The deadline for each county in Pennsylvania varies.  The deadline to file a property tax appeal in most Pennsylvania counties ranges between August 1, 2026, and October 1, 2026.  In Allegheny County, the 2027 deadline is September 1, 2026. 

Property taxes are based on assessed value. Assessed values are taxed at the millage rates set by your county, school district, and local municipality. Assuming no change in millage rates, a lower assessed value means lower property taxes.

Taxing authorities may increase their millage rates to avoid a large drop in tax revenue resulting from fewer assessed dollars. If millage rates increase, each assessed dollar will be taxed more. In a rising millage rate environment, property owners will see tax increases unless they can reduce their assessed value via a tax assessment appeal.

The answer to this question will vary based on each property’s use, market value, current assessed value, improvements made to the property, and the strategies available to obtain a reduction for that property. The attorneys in Meyer, Unkovic & Scott’s Real Estate Group have substantial experience representing property owners with property tax assessment appeals throughout Pennsylvania.

Our broad range of experience includes handling appears for clients in virtually every type of property, including:

• Apartment complexes
• Banks
• Condominiums
• Convention centers
• Hotels
• Industrial plants
• Life science facilities
• Multifamily housing
• Office towers
• Restaurants
• Retail establishments
• Shopping centers, malls, and strip malls
• Single family residences
• Storage facilities
• Tax exemptions for charitable, educational, religious, trade, and other uses
• Warehouses