McHenry County Property Tax Appeal, Illinois

Travis Bunn·Updated July 24, 2026

McHenry County is located in northeastern Illinois with Woodstock serving as the county seat. With a 2026 population estimated at approximately 319,772, major population centers include Crystal Lake (the largest city), Algonquin, McHenry, Lake in the Hills, and Huntley. Property tax appeals are particularly critical in McHenry County as it has one of the highest property tax burdens in Illinois, with median annual tax bills significantly exceeding both state and national averages. The county's effective tax rate of 2.09% to 2.26% is more than double the national median of 1.02%, making thorough assessment reviews essential for homeowners seeking to ensure fair taxation.

Notable cities: Woodstock, Crystal Lake, Algonquin, McHenry, Lake in the Hills, Huntley

Median Home

$297,576

Tax Rate

2.18%

Annual Tax

$7,056

Population

319,772

On the typical McHenry County home, valued near $297,576 at the county’s effective tax rate of 2.18%, an over-assessment of even 10% means you are overpaying year after year until you appeal it. Here is how to find out if yours qualifies.

2026 Appeal Deadline: 30 days after the publication date of your assessment notice

McHenry County follows a rolling deadline system by township. You must file your appeal within 30 days after the publication date of your assessment notice. Assessment notices are typically published in spring (mid-April through May), making most appeal deadlines fall in May or June. The deadline is strictly enforced - complaints must be officially postmarked (not metered mail), hand-delivered, or filed online on or before the deadline date.

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Aerial view of an Illinois residential neighborhood. McHenry County appeal guide.

How McHenry County Assesses Property

33.33%of market value

Assessed by: McHenry County Office of Assessments (Supervisor of Assessments) in coordination with township assessors

Assessment cycle: annual

Notices typically mailed: Spring (mid-April through May)

In McHenry County, properties are assessed at 33.33% of their fair market value as required by Illinois law, meaning your assessed value is one-third of your property's market value. For example, if your home's market value is $297,576 (the county median), at Illinois's 33.33% assessment ratio your assessed value would be $99,192, resulting in approximately $7,056 in annual taxes at the county's effective rate of 2.18%. Beginning in 2026, assessment notices are only mailed to properties with changes, farm properties, or new construction; all others must check their assessment online.

The Appeal Process

Appeals are heard by the Board of Review. The McHenry County Board of Review operates as a quasi-judicial body that reviews evidence from both property owners and township assessors. Hearings are scheduled every 15 minutes for residential properties, and the Board may issue a tentative decision based on submitted evidence before scheduling a formal hearing. If you agree with the tentative decision, you can sign a hearing waiver; otherwise, you must appear at the scheduled hearing time.

Step 1: Review your assessment notice when it arrives in spring and compare your assessed value to similar properties using the county's online property inquiry system at https://mchenryil.devnetwedge.com

Step 2: Contact your township assessor for an informal review before the 30-day deadline expires - many assessors will agree to adjust assessments through stipulation without requiring a formal hearing

Step 3: If the informal review is unsuccessful or you cannot reach an agreement, complete Form PTAX-230 (Non-farm Assessment Complaint) and the comparable sales grid with 3-5 comparable properties sold near January 1 of the assessment year

Step 4: File your completed appeal with supporting evidence (comparable sales, photos, appraisals, property record cards) through the online portal, by mail, or in person within 30 days of assessment publication

Step 5: Choose whether to submit evidence for a decision without appearing or request a formal hearing before the Board of Review (hearings typically last 15 minutes for residential properties)

Step 6: Attend your scheduled Board of Review hearing if requested, where both you and the township assessor will present evidence - the three-member Board will render a written decision upholding or adjusting your assessed value

Step 7: If unsatisfied with the Board of Review decision, appeal in writing to the Illinois Property Tax Appeal Board (PTAB) in Springfield or file a tax objection complaint in circuit court

Required form: Form PTAX-230 (Non-farm Assessment Complaint) or county-provided online complaint form

Filing Methods

online:McHenry County Board of Review online portal at https://www.mchenrycountyil.gov/departments/assessments/submit-your-complaint - Complaints can ONLY be submitted using this portal; emailed electronic complaints will not be accepted

mail:Office of Assessments, 2200 North Seminary Ave, Woodstock, IL 60098 (must be officially postmarked, not metered mail)

in-person:Office of Assessments, 667 Ware Road, Room 106, Woodstock, IL 60098

Evidence to Bring

Completed comparable sales grid with 3-5 similar properties sold near January 1 of the assessment yearProperty record cards and photographs of your property and comparable propertiesRecent independent appraisal (if available)Real estate transfer declarations, deeds, or purchase contractsInterior/exterior photos with date stamps (especially for condition-based appeals)Documentation of property defects, needed repairs, or depreciation factors

McHenry County Assessor Contact

McHenry County Office of Assessments

Website: https://www.mchenrycountyil.gov/departments/assessments

Online Portal: https://www.mchenrycountyil.gov/departments/assessments/submit-your-complaint

Hours: 8:00 AM to 4:30 PM Central Time, Monday through Friday

Tax Exemptions in McHenry County

General Homestead Exemption

$8,000 reduction in assessed value (increased from $6,000)

Reduces the equalized assessed value for owner-occupied primary residences

Eligibility: Available for all owner-occupied residences with no age requirement. Must be the primary residence of the property owner.Deadline: Applications are typically due annually through the County Assessor's office

Senior Citizens Homestead Exemption

$8,000 reduction in assessed value

Provides an additional reduction in assessed value for qualifying seniors

Eligibility: Owner or person with equitable interest must be 65 years of age or older during the taxable year. Property must be owner-occupied as primary residence.Deadline: Annual application required through the McHenry County Supervisor of Assessment Office

Senior Citizens Assessment Freeze Homestead Exemption (Low-Income)

Freezes assessed value at base year (year prior to first qualifying)

Freezes the equalized assessed value at the base year level to prevent increases due to inflation

Eligibility: Must be 65 or older, own and occupy the property as principal residence, and meet maximum household income limits. For 2026 (payable 2027), maximum income is $75,000; for 2027 (payable 2028), $77,000; for 2028 (payable 2029), $79,000. Income includes all household members as of January 1.Deadline: Annual application required on Form PTAX-340. Must reapply each year, though automatic renewals were granted during COVID-19.

Homestead Exemption for Persons with Disabilities

Reduction in equalized assessed value

Reduces assessed value for homeowners with disabilities

Eligibility: Must have a qualifying disability and own/occupy the property as principal residenceDeadline: Annual application required through the County Assessment Office

Disabled Veterans Standard Homestead Exemption

$5,000 reduction in assessed value for qualifying veterans; veterans with 70% or greater service-connected disability are exempt from property tax

Provides property tax relief for veterans with service-connected disabilities

Eligibility: Must be a veteran with a service-connected disability as certified by the U.S. Department of Veterans AffairsDeadline: Annual application required through the County Assessment Office

Returning Veterans Homestead Exemption

$5,000 reduction in equalized assessed value for two years

Two-year exemption for veterans returning from active duty in armed conflict

Eligibility: Must have returned from active duty in armed conflict. Exemption begins the year you return from service.Deadline: Apply through the County Assessment Office starting in the tax year you return from duty

Home Improvement Exemption

Maximum exemption of $75,000 in market value (resulting in maximum $25,000 assessment exemption at 33.33% ratio)

Exempts the increased value from residential improvements for up to 4 years

Eligibility: Property must be owner-occupied residential. Applies to renovations, additions, and improvements.Deadline: Must apply through township assessor or County Assessment Office

McHenry County Appeal Packet · $49

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Frequently Asked Questions

What is the deadline to appeal my property taxes in McHenry County?

You must file your property tax appeal within 30 days after the publication date of your assessment notice in McHenry County. Assessment notices are typically published in spring, with most townships publishing in mid-April through May, making most appeal deadlines fall in May or June. This is a strict rolling deadline by township, so check your specific assessment notice publication date carefully. The deadline is firmly enforced - appeals must be officially postmarked (not metered mail), filed online through the county portal, or hand-delivered to the Office of Assessments on or before the 30th day.

How do I file a property tax appeal online in McHenry County?

McHenry County requires all online appeals to be filed through their official Board of Review portal at https://www.mchenrycountyil.gov/departments/assessments/submit-your-complaint. You must complete the complaint form and comparable sales grid, save them to your computer, then upload them along with supporting evidence through the portal. Electronic complaints sent via email will NOT be accepted by the Board of Review - you must use the official online portal. After submitting, enter your email address to receive a confirmation copy of your complaint and evidence. For assistance with the e-filing system, contact the Office of Assessments at (815) 334-4290 during business hours (8:00 AM to 4:30 PM).

What is the homestead exemption worth in McHenry County?

The General Homestead Exemption in McHenry County provides an $8,000 reduction in your property's assessed value (recently increased from $6,000). For the typical McHenry County home with an effective tax rate of 2.18%, this $8,000 assessed value reduction translates to approximately $174 in annual property tax savings. This exemption is available to all owner-occupied primary residences regardless of age or income, though you must apply annually through the McHenry County Assessor's office. Senior citizens age 65 and older can receive an additional $8,000 Senior Citizens Homestead Exemption, and low-income seniors may qualify for the Assessment Freeze which can provide even greater savings by locking in your assessed value.

Should I contact my township assessor before filing a formal appeal in McHenry County?

Yes, contacting your township assessor for an informal review before filing a formal Board of Review appeal is highly recommended in McHenry County. Many township assessors will review your evidence and agree to adjust your assessment through a stipulation without requiring a formal hearing, saving you time and effort. Township assessors often contact property owners before scheduled hearings to review findings and reach fair agreements. However, you must still act within the 30-day appeal deadline - don't let informal discussions cause you to miss the filing deadline. If you cannot reach an agreement with your township assessor during the informal review, you can then proceed with filing the formal PTAX-230 complaint form with the Board of Review.

How much can I save by appealing my property taxes in McHenry County?

In McHenry County, with a median home value of $297,576 and an effective tax rate of 2.18%, even a 10% reduction in your assessed value can save you over $700 annually. One source indicates successful appeals could save homeowners $1,073 or more per year depending on the degree of over-assessment. The actual savings depend on how much your property is over-assessed and the evidence you can provide. With the median McHenry County property tax bill at $7,056 - nearly three times the national median of $2,400 - even modest reductions can result in substantial ongoing savings. Remember that property tax savings from a successful appeal continue year after year until the next reassessment, multiplying the value of a successful appeal.

What evidence do I need for a successful property tax appeal in McHenry County?

McHenry County requires you to complete a comparable sales grid with 3-5 similar properties that sold close to January 1 of the assessment year, located within 0.5 miles when possible, with similar size, age, and condition. You should include property record cards and photographs for both your property and all comparable properties. Additional strong evidence includes a recent independent appraisal (especially if done for appeal purposes), real estate transfer declarations or deeds showing actual sale prices, and interior/exterior photos with date stamps if you're claiming condition issues or needed repairs. The Board of Review makes decisions based on either comparable sales demonstrating over-assessment or equity evidence showing your property is assessed higher than similar properties. Township assessors will provide small photos of your property to the Board, but larger detailed photos are helpful for condition-based appeals.

What happens at a Board of Review hearing in McHenry County?

McHenry County Board of Review hearings are scheduled every 15 minutes for residential properties and last approximately 30 minutes for commercial properties. Both you and your township assessor will have the opportunity to present evidence and supporting documentation to the three-member Board of Review panel. Before scheduling a formal hearing, the Board may issue a tentative decision based on your submitted evidence - if you agree with their tentative decision, you can sign a hearing waiver and avoid appearing; if you disagree, you must attend the scheduled hearing. During the hearing, the Board reviews all evidence and renders a decision either upholding the assessor's value or adjusting the assessed value. You will receive the Board's final decision in writing, and if you remain unsatisfied, you can appeal further to the Illinois Property Tax Appeal Board (PTAB) in Springfield.

Can I still appeal if I disagree with the Board of Review decision in McHenry County?

Yes, if you are unsatisfied with the McHenry County Board of Review's decision, you have two appeal options at the state level. You can file a written appeal to the Illinois Property Tax Appeal Board (PTAB) in Springfield using their prescribed residential, commercial, industrial, or farm forms available at www.ptab.illinois.gov, or you can file a tax objection complaint in circuit court in McHenry County. In either case, Illinois law requires you to pay your property taxes pending the outcome of your appeal of the Board of Review's decision. The Board of Review serves as the final local authority for assessment adjustments at the county level, so appeals beyond this point move to state-level adjudication. You must have first filed with the county Board of Review before you can appeal to PTAB or circuit court.

Official Resources

McHenry County Office of Assessments →

Official county assessor website with assessment information, exemption applications, Board of Review details, and property search tools.

McHenry County Board of Review Online Appeal Portal →

Official online portal for filing property tax assessment appeals - the only accepted method for electronic appeal submissions.

McHenry County Property Tax Inquiry System →

Search property assessments, view tax bills, pay taxes online, and access assessment notices for all parcels in McHenry County.

Illinois Department of Revenue - Property Tax Appeals →

State guidance on property tax assessment appeals, including PTAX-230 form downloads and instructions for appealing to county boards of review.

Illinois Property Tax Appeal Board (PTAB) →

State-level appeal board for property owners dissatisfied with county Board of Review decisions, with filing forms and procedures for further appeals.

For state-wide appeal information including Illinois's assessment ratio and deadlines, see our Illinois Property Tax Appeal Guide →

Considering professional help with your appeal? Compare pricing, coverage, and pros/cons in our Best Property Tax Appeal Services (2026) or browse side-by-side service comparisons →

More Illinois Counties

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← All Illinois property tax appeal info

Sources: https://www.mchenrycountyil.gov/departments/assessments | https://www.mchenrycountyil.gov/departments/assessments/submit-your-complaint | https://www.mchenrycountyil.gov/departments/assessments/contact-us | https://tax.illinois.gov/localgovernments/property/appeals.html | https://www.ownwell.com/trends/illinois/mchenry-county | https://smartasset.com/taxes/illinois-property-tax-calculator | https://worldpopulationreview.com/us-counties/illinois/mchenry-county

Last verified: 2026-07-24