How Everyone Built Marengo a $4,957 Tax Bill

Marengo's property tax rate has fallen 22% in four years. In 2021, the composite rate for a home inside city limits was 9.21 per $100 of assessed value. By 2025, it was 7.22. ¹ That looks like relief. It is not. Most homeowners are paying more, not less, because the value the rate is applied to has been rising faster than the rate has been falling.

The mechanism is simple. Illinois caps how fast taxing bodies can increase their levies (the dollar amount they collect). But the tax rate is the levy divided by the total assessed value of property in the district. When property values surge, the rate drops, even if the levy keeps growing. Marengo's total equalized assessed value jumped 32% between 2023 and 2025, from $181 million to $238 million. ^{1 15 16} A 22% rate cut against a 32% value increase means a higher bill.

McHenry County Clerk, City of Marengo audits

That is the math. But the math does not explain why the bill is so high in the first place. For that, you need to understand who is levying, how much, and why Illinois homeowners carry one of the heaviest property tax burdens in the nation.

A study released March 30 by Cook County Treasurer Maria Pappas found that property taxes in Cook County grew 182% over the past 30 years, nearly double the rate of inflation. ²

“School boards didn't take the hint.” ²⁵

Governor J.B. Pritzker, responding to the Pappas report, March 30

The state has increased K-12 funding by over $2.5 billion since 2017, but that money has not slowed the growth in local levies. The framing from Springfield is that this is a local problem. The numbers in Marengo suggest it is everyone's problem: the state sets the rules, underfunds schools relative to the national average, and twelve local bodies each set their own levy with no coordination among them. ²⁵

Median home value $229,900

× Assessment ratio 33.34%

Assessed value $76,649

− Homeowner exemption −$8,000

Taxable base $68,649

× Composite rate (per $100 EAV) 7.22

Annual tax bill $4,957

McHenry County Clerk, Census Bureau, Illinois Dept. of Revenue

Cook County's scale is different, but the structural forces are the same. The state has roughly 7,000 units of local government, more than any other state, and it pushes an unusually large share of public costs onto property owners. What follows is a guide to how that system works in Marengo, built entirely from public records. ^{1 3 4}

Take a home at Marengo's median value: $229,900, according to the Census Bureau. ²³ The county assessor values it at 33.34% of market value, producing an assessed value of $76,649. Subtract the $8,000 homeowner exemption and you have a taxable base of $68,649. ⁴ Twelve separate taxing bodies then apply their rates to that number. The result: $4,957 a year. That is $413 a month. On a median household income of $72,586, the tax bill alone consumes 6.8% of gross income, before the mortgage, before insurance, before maintenance. ^{1 24}

The twelve bodies are listed in the chart. Two school districts (Marengo-Union Elementary District 165 and Marengo Community High School District 154) take 55.3% of the total. ¹ That means $2,738 of the median bill goes to schools. The city of Marengo takes 12.4%, or $612. McHenry County takes 6.9%, or $342. The remaining eight bodies, from the fire district to the township, split 26.3%.

McHenry County Clerk, Tax Code 11001, 2025 rates

None of these bodies coordinates its levy with the others. Each sets its own budget, calculates its own rate, and sends the number to the county clerk. The homeowner receives one bill. ¹

The reason schools dominate the bill is not local. It is a state-level policy choice that has persisted for decades.

Nearly 63% of Illinois public school funding comes from local property taxes, according to the Civic Federation. ⁵ Nationally, the local share averages closer to 45%. That gap lands on homeowners. Statewide, school districts account for 55% to 67% of all property taxes collected. In collar counties like McHenry, the share is closer to 70%. ⁵

The imbalance shows up sharply when you compare neighboring districts. Marengo High School District 154 draws 66% of its revenue from local sources and 27% from the state. Marengo-Union Elementary District 165 is slightly less dependent: 54% local, 32% state. ⁶

Fifteen miles northwest, Harvard Community Unit School District 50 draws 55% of its revenue from the state and only 35% from local property taxes. ⁷ The difference is the Evidence-Based Funding formula, enacted in 2017, which directs state dollars toward districts with lower property wealth and higher student need. The formula is working as designed. But it means Marengo homeowners fund their schools more heavily than homeowners in communities where the state picks up a larger share.

The single largest structural lever for reducing Marengo property tax bills would be for Springfield to increase the state share of school funding. Rate caps, levy limits, and consolidation are marginal adjustments by comparison.

That structural tension does not excuse local overreach. In 2025, over 400 Marengo-area homeowners, HOAs, and businesses filed a tax rate objection lawsuit against District 154. A judge found that the district had accumulated $4.5 million in its Operations and Maintenance fund while spending only about $1.42 million a year on maintenance. A $2.5 million transfer between funds was ruled unlawful. ⁸ The district was ordered to repay $364,000 for its 2022 levy and agreed to return another $241,000 for 2023. ⁹ Riley Community Consolidated School District 18, an elementary feeder, settled a similar lawsuit for $1.2 million. ⁸ Combined: $1.8 million returned to taxpayers in a single year.

Illinois has a law designed to prevent exactly that kind of creep. It is called the Property Tax Extension Limitation Law, or PTELL. ³ In McHenry County, the law has been on the books since 1991. It caps annual levy increases at the lesser of 5% or the rate of inflation. ³ The current cap is 2.9%. ³

In practice, the cap leaks. It has at least ten legal exceptions, and three of them were tested in McHenry County in the past two years. ¹¹

In November 2024, the McHenry County Conservation District asked voters to override PTELL. The referendum passed by 850 votes and will generate roughly $3 million a year in new revenue. ¹² One month later, the McHenry County Board debated using a provision that allows a district to reset its levy to the highest level of the prior three years. That lookback was voted on multiple times and never got enough votes to pass. The board ultimately approved a CPI-based levy increase, 9 to 8. ¹³ In March 2024, the Marengo Park District asked voters in three adjacent townships to annex into the district. Annexation would have expanded the district's tax base by adding new payers, not by raising rates on existing ones. All three referenda were rejected by margins of 60% to 68%, in the same election where voters approved a city sales tax for road maintenance. ¹⁴

The other major exceptions are new construction (assessed value of new buildings is added outside the cap), debt service on voter-approved bonds (uncapped), and expired TIF districts (returning EAV treated as new growth). ¹¹ If every taxing body had taken the maximum PTELL increase every year since 1993, a $100 levy would have grown to $222, a 122% increase. Cook County's actual growth was 182%. ^{2 3} The Civic Federation calculated that the gap, $1.3 billion in excess collections between 2006 and 2023, flowed through precisely these exceptions. ¹⁰

Certain levies bypass PTELL entirely. Pension contributions, tort liability, workers' compensation, and audit costs are not subject to the cap. ¹¹ That matters in Marengo because the police pension obligation is large relative to the city's budget.

The Marengo Police Pension Fund has set aside less than half of what it owes. The unfunded liability is $9.3 million against a total accrued liability of $17.8 million. ¹⁷

Forty-eight cents for every dollar promised. That is what Marengo has set aside for police pension benefits. The obligation is not optional. The payments will grow every year until 2040.

The direction is improving: the funded ratio climbed from 36.8% in 2023 to 47.8% this year. ^{17 19} That is still below the average downstate police pension fund (59%), but the gap is closing. ¹⁸ The city's IMRF fund, covering non-police employees, is 95.3% funded. ¹⁹

The obligation is not discretionary. State law requires the city to contribute $882,000 this year. ¹⁷ That is roughly a third of the city's total property tax levy. The fund covers 12 active officers, 9 service retirees, 3 disability recipients, and 2 surviving spouses. ¹⁷ The city is on a state-mandated schedule to reach 90% funding by 2040, and the annual payments will grow every year until it gets there. About $204 of the median homeowner's annual bill goes directly to police pension funding.

All of these investments, accumulated over decades, are pooled through IPOPIF, the statewide police pension investment fund. Marengo's $8.4 million in assets are managed by State Street in a consolidated pool. ¹⁷ The fund earned $749,000 in investment income last year. The city has no control over investment strategy.

Ownwell property tax data, 2025

Marengo's effective property tax rate is 2.05%, according to Ownwell's analysis of county records. ²⁰ That is the lowest among the eight largest municipalities in McHenry County. The county average is 2.42%. Woodstock is 2.67%. Crystal Lake is 2.55%. Even Huntley, the county's fastest-growing community, is 2.22%. ²⁰

Ownwell reports the median actual bill in Marengo at $5,545, also the lowest among those municipalities. ²⁰ That figure is higher than the $4,957 calculated above because it reflects the full distribution of home values and tax codes across the city, not just the median-value home in a single tax code. The county median is $7,056. ²²

In absolute terms, Marengo homeowners are not wrong to feel the weight. Illinois has the second-highest effective property tax rate in the nation, behind only New Jersey, according to the Tax Foundation. ²¹ The state effective rate is 2.07%. ²¹ The national median is 0.89%. ²² Neighboring states are materially lower: Wisconsin's effective rate is 1.66%, Iowa's is 1.57%. ²¹ Marengo's 2.05% is below the state average, below the county average, and still more than double what homeowners pay in most of the country.

The rate on your bill will keep changing. Assessed values shift with the market. Levies compound under PTELL. State funding formulas evolve. But the structure underneath, twelve overlapping taxing bodies funded through property taxes because the state does not adequately fund its own schools, has been in place for decades. Marengo's rate is the lowest among major McHenry County municipalities. Marengo homeowners still pay more than double the national average. The first fact reflects local fiscal management. The second reflects a system that will not change without action from Springfield.