An analysis of Cook County’s 1.8 million property tax bills for 2022 shows that school districts are chiefly responsible for hefty tax bills that are due Dec. 1, according to Treasurer Maria Pappas.

The median residential tax bill in the north and northwest suburbs increased 15.7%, the largest percentage increase in at least 30 years, the analysis found. These higher tax bills are the result of increased levies — the amount of money sought by taxing districts — and a shift of the tax burden onto homeowners from businesses as a result of reassessments in the northern suburbs.

Treasurer’s Office researchers Hal Dardick and Todd Lighty led the analysis. Pappas hired the former Chicago Tribune investigative journalists to head up her office’s think tank. The analysis is the latest addition to the Pappas Studies, a series of examinations of the complex property tax system available at cookcountytreasurer.com.

Key findings of the analysis show:

• Of 940 taxing agencies in the county, 676 — or 71.9% — increased taxes.
• The amount of taxes billed to property owners countywide rose more than $909 million from $16.7 billion to $17.6 billion, a 5.4% increase over 2021. Homeowners are shouldering $599.1 million, or two-thirds of the increase, while commercial properties are picking up one-third and owe an additional $314.4 million.
• In newly reassessed north and northwest suburbs, taxes rose $331 million — with a $387 million, or 12.9%, increase on residences and a $56 million, or 2.7%, decrease on commercial properties.
• In the south and southwest suburbs, taxes rose $173 million from $3.88 billion to $4.06 billion. Residential taxes increased $98 million, or 4.1%, from $2.4 billion to $2.5 billion, while taxes on commercial properties increased $75 million, or 5.1%, from $1.48 billion to $1.56 billion.

Cook County is divided into three areas for reassessments: the city of Chicago, north suburbs and south suburbs. The county assessor calculates new values for properties in each region once every three years, a process known as triennial reassessments.

Property values are one factor in the complex property tax system. Local units of government set tax levies that determine how much money they need to operate. The assessed values of properties and amounts of levies determine the tax rates, which vary widely among communities.

State law allows school districts to hike taxes by the prior year’s increase in the consumer price index, or 5%, whichever is less. Because the CPI increased by 7% in 2021, school districts were allowed a 5% increase. But the overall percentage increase was higher, partly due to a new provision called recapture.

Recapture, which took effect in the 2021 tax year due to a change in state law, allows schools and other taxing bodies to recover money that was refunded to property owners whose assessments were lowered by the Illinois Property Tax Appeal Board, state courts or county offices.

Recapture accounted for $203.7 million countywide for 2022, a $72.7 million increase from last year.

Significant increases in the amount of money the city of Chicago and Chicago Public Schools said they needed to operate, coupled with the recapture provision and higher tax increment financing district bills, boosted the overall property tax burden in Chicago by $410 million from $7.65 billion to $8.1 billion. That broke down as a $296 million, or 7.8%, increase on commercial properties and a $115 million, or 3%, increase on residential properties.

Chicago Public Schools recaptured $50.8 million for the 2022 tax year. As a home rule municipality, the city of Chicago is unable to recapture taxes, as the state law applies only to non-home rule communities.

The Treasurer’s analysis revealed that throughout Cook County in 2022, the amount owed to tax increment financing districts increased $124.6 million from $1.43 billion to $1.56 billion. TIF district increases account for about 13.7% of the overall rise in what property owners across the county owe.

Second Installment 2022 tax bills are set to be mailed Nov. 1 and are due Dec. 1. Property owners who don’t want to wait for their bills to arrive in the mail can pay their taxes online now at cookcountytreasurer.com. Partial payments are accepted.