A bill set to be introduced Tuesday evening to Allegheny County Council would mandate regular countywide property reassessments.

Under the proposed legislation, the county would reassess property values every three years, with the first required reassessment mandated in 2028.

The measure would ensure everyone pays a fair amount in property taxes and provide predictability for municipalities and school districts that rely on tax revenue to pay their bills, Councilwoman Bethany Hallam, a Democratic at-large council member who co-sponsored the bill, told TribLive on Tuesday.

It’s been over a decade since the last countywide property reassessment. There have since been debates, lawsuits and even a push for state legislation mandating reassessments throughout the commonwealth.

Pennsylvania is the only state that does not require regular reassessments. Counties determine independently when to reassess property values.

When counties wait for a long period of time to hold countywide reassessments, imbalances can emerge in assessed values.

Similar homes in the same areas can be assessed at drastically different values, based on whether a specific property has been reassessed or not. That means homeowners can pay significantly different amounts of taxes on properties that are actually worth the same amount.

“What happens when so much time goes between reassessments is we see this gross inequity in property taxes,” Hallam said, explaining that some property owners pay more than their fair share — and others don’t pay enough. “It’s all about making things fair. I think everyone could probably agree taxes should be fair.”

Hallam on Tuesday told TribLive the measure also would make taxes more predictable for both homeowners and local governments and school districts.

Currently, reassessments are happening piecemeal. A homeowner whose property is suddenly reassessed could be unexpectedly faced with a higher tax bill. Hallam said regular reassessments would reduce those kinds of drastic changes.

Post-pandemic reassessments have allowed large commercial properties — especially Downtown Pittsburgh’s office towers — to significantly reduce their taxes. That has hit local government and school district budgets hard in recent years.

While a countywide reassessment may create more stability for municipalities and school districts that are crafting their budgets based on projected tax revenues, it will not allow them to rake in lots of extra revenue. A Pennsylvania anti-windfall rule mandates that millage rates be adjusted to make reassessments revenue neutral.

Hallam co-sponsored the bill with council members Dan Grzybek, D-Bethel Park, and Lissa Geiger Shulman, D-Hampton.