McHenry County Property Tax Appeal — Illinois

Rob Hartley·Updated February 15, 2026

McHenry County, Illinois is located in the northeastern part of the state and is home to over 310,000 residents. The county seat is Woodstock, with major population centers including Crystal Lake, Algonquin, and McHenry. Property tax appeals are particularly important here as McHenry County has one of the highest property tax burdens in Illinois, with a median property tax bill of $5,226 to $7,219 annually, significantly above the national median of $2,400. The county's median home value ranges from $249,700 to $328,900, with an effective tax rate of 2.09% to 2.18%, more than double the national average of 1.02%.

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

Median Home

$328,900

Tax Rate

2.18%

Annual Tax

$7,176

Population

310,000

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

You must file your appeal within 30 days after the publication date of your assessment notice. Assessment notices are typically mailed in spring (mid-April), making most appeal deadlines fall in May or June.

Property in McHenry County, Illinois — local tax assessment and appeal guide

How McHenry County Assesses Property

33.33%of market value

Assessed by: McHenry County Office of Assessments

Assessment cycle: annual

Notices typically mailed: Spring (mid-April)

In McHenry County, properties are assessed at 33.33% of their market value, as required by Illinois law. This means your assessed value is one-third of your property's fair market value. For example, if your home's market value is $328,900 (the county median), at Illinois's 33.33% assessment ratio your assessed value would be $109,633, resulting in approximately $7,176 in annual taxes at the county's effective rate of 2.18%.

The Appeal Process

Appeals are heard by the Board of Review. The Board of Review will schedule a hearing where you can present your evidence and argue for a lower assessment. The Board will review your evidence and render a decision regarding your property's value.

Step 1: Review your assessment notice when it arrives in mid-April and compare your assessed value to similar properties in your area

Step 2: Contact your township assessor for an informal review before the 30-day deadline - they may agree to adjust your assessment without a formal appeal

Step 3: If informal review is unsuccessful, file form PTAX-230 with the McHenry County Board of Review within 30 days of assessment publication

Step 4: Gather evidence including recent appraisal, comparable sales data, photos of property condition issues, and repair estimates

Step 5: Attend your Board of Review hearing to present your evidence and make your case for a lower assessment

Step 6: If unsatisfied with the Board of Review decision, appeal to the Illinois Property Tax Appeal Board (PTAB) in Springfield

Required form: PTAX-230 (Property Tax Appeal Form)

Filing Methods

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

mail:Office of Assessments, 2200 North Seminary Ave, Woodstock, IL 60098

email:assessments@https://mchenrycountyil.gov

Evidence to Bring

Recent property appraisalComparable property sales dataPhotos of property condition issuesRepair estimates or contractor bidsEvidence of incorrect property characteristics

McHenry County Assessor Contact

McHenry County Office of Assessments

Phone: (815) 334-4290

Address: 2200 North Seminary Ave, Woodstock, IL 60098

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

Online Portal: https://mchenryil.devnetwedge.com/

Tax Exemptions in McHenry County

Homestead Exemption

$6,000 reduction in assessed value (increasing to $8,000)

Reduces the equalized assessed value for all owner-occupied residences

Eligibility: Must own and occupy the property as primary residence as of January 1stDeadline: Check with township assessor

Senior Citizens Homestead Exemption

$8,000 reduction in assessed value

Additional reduction for homeowners aged 65 or older

Eligibility: Must be 65+ years old and own/occupy the propertyDeadline: Contact County Assessments Office

Senior Citizens Assessment Freeze

Prevents assessment increases due to inflation

Freezes the assessed value at base year level for qualifying seniors

Eligibility: Age 65+, household income under $75,000 for 2026Deadline: Forms available March 2026

Disabled Veterans Exemption

$5,000 reduction; 70%+ disabled veterans exempt from all property tax

Exemption for veterans with service-connected disabilities

Eligibility: Service-connected disability verified by VADeadline: Contact County Assessments Office

Homestead Exemption for Persons with Disabilities

$2,000 reduction in equalized assessed value

Annual exemption for disabled homeowners

Eligibility: Unable to engage in substantial gainful activity for 12+ monthsDeadline: Must renew annually

Official Resources

McHenry County Assessments Department →

Official county assessments office website with forms, rules, and contact information for property tax appeals.

McHenry County Property Tax Inquiry Portal →

Search for property information, view tax bills, and access assessment data for properties in McHenry County.

Illinois Property Tax Appeal Board →

State-level appeal option if you're unsatisfied with your McHenry County Board of Review decision.

McHenry County Forms and Rules →

Download property tax appeal forms, exemption applications, and review filing requirements.

Check Your McHenry County Assessment

Enter your address to see if your McHenry County property is overassessed.

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Frequently Asked Questions

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

The deadline to appeal your property taxes in McHenry County is 30 days after the publication date of your assessment notice. Assessment notices are typically mailed out in mid-April, which means most appeals must be filed by mid-May. It's crucial to mark this date on your calendar as soon as you receive your notice, as the Board of Review strictly enforces this deadline and late appeals are not accepted. If you miss the deadline, you'll have to wait until the following year to appeal your assessment.

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

While McHenry County offers an online property tax inquiry system at https://mchenryil.devnetwedge.com, formal appeals must be filed using form PTAX-230. You can submit your appeal by email to assessments@https://mchenrycountyil.gov, by mail to 2200 North Seminary Ave, Woodstock, IL 60098, or in person at 667 Ware Road, Room 106, Woodstock. Include all supporting documentation with your appeal form, such as comparable sales data, photos, or a recent appraisal. Many property owners first contact their township assessor for an informal review before filing a formal appeal.

What is the homestead exemption worth in McHenry County?

The general homestead exemption in McHenry County currently provides a $6,000 reduction in your property's assessed value, which is increasing to $8,000. At the county's 2.18% effective tax rate, this translates to approximately $130-174 in annual tax savings. Senior citizens can receive an additional $8,000 senior homestead exemption, and those with household incomes under $75,000 may qualify for the assessment freeze. To receive the homestead exemption, you must own and occupy the property as your primary residence as of January 1st of the tax year.

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

At a McHenry County Board of Review hearing, you'll present your case for why your property assessment should be lowered. The Board will review your evidence, which should include comparable property sales, photos of any condition issues, repair estimates, or a professional appraisal. You'll have the opportunity to explain your position and answer questions from Board members. The hearing is relatively informal, and many homeowners represent themselves successfully. After reviewing all evidence, the Board will make a decision to either maintain, increase, or decrease your assessment.

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

The amount you can save through a successful property tax appeal in McHenry County varies significantly based on your property's overassessment. With the county's high effective tax rate of 2.18%, even a modest reduction in assessed value can yield substantial savings. For example, if your appeal results in a $30,000 reduction in assessed value (from $109,633 to $79,633), you would save approximately $654 annually. Some property owners have reported savings of $1,000 or more per year, and these savings continue each year until your next reassessment.

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

For a successful McHenry County property tax appeal, you should gather several types of evidence. The most compelling evidence includes recent sales of comparable properties in your neighborhood (ideally 3-5 properties sold within the last year), a professional appraisal conducted for appeal purposes, photos documenting any property condition issues, and contractor estimates for necessary repairs. You should also verify that your property characteristics on file are correct, as errors in square footage, number of bedrooms, or lot size are common grounds for appeal. The more comprehensive your evidence package, the better your chances of receiving a reduction.

Can I appeal my McHenry County property taxes if I missed the 30-day deadline?

Unfortunately, if you miss the 30-day appeal deadline after your assessment notice publication, you cannot appeal for that tax year with the McHenry County Board of Review. The deadline is strictly enforced with no exceptions. However, you still have options: you can prepare for next year's appeal by gathering evidence and monitoring comparable sales, or if you believe there was a significant error, you may be able to file a Certificate of Error with the County Assessor. Some property owners also hire attorneys to explore appeals through the Illinois Property Tax Appeal Board, though this typically requires having first filed with the local Board of Review.

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

Yes, contacting your township assessor before filing a formal appeal is highly recommended in McHenry County. Many township assessors, including those in McHenry Township, Nunda Township, and others, offer informal reviews during the 30-day appeal period. During an informal review, the assessor will examine your evidence and may agree to adjust your assessment without requiring a formal Board of Review hearing. This can save you time and potentially achieve the same result more quickly. If the informal review doesn't result in a satisfactory adjustment, you can still proceed with a formal appeal to the Board of Review within the 30-day deadline.

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.tax-rates.org/illinois/mchenry_county_property_tax | https://www.ownwell.com/trends/illinois/mchenry-county | https://smartasset.com/taxes/illinois-property-tax-calculator | https://www.mchenrycountyil.gov/departments/assessments/forms-and-rules

Last verified: 2026-02-15