Does your Lake County assessment notice make you wonder how the number was set and what it means for your tax bill? You are not alone. Property taxes can feel complex, especially if you live in Highland Park or Lake Forest where values shift with the market. This guide breaks down how reassessment works, how an appeal flows, and what actually influences the bill you pay. Let’s dive in.
Lake County assessment basics
Who does what
- Lake County Assessor sets assessed values and manages exemptions and informal reviews.
- Lake County Board of Review hears formal assessment complaints after the assessor’s actions.
- Lake County Treasurer/Collector issues tax bills and collects payments.
- Illinois Department of Revenue (IDOR) applies equalization factors and oversees uniformity statewide. The Illinois Property Tax Appeal Board (PTAB) handles state-level appeals after local remedies.
How value becomes a tax bill
- Market value, also called fair cash value, is the price a willing buyer would pay a willing seller as of January 1 for that tax year.
- The assessor sets an assessed value, and for residential property in Illinois it is generally one-third of market value, about 33.33%.
- An equalization factor is applied to create Equalized Assessed Value (EAV).
- Exemptions, such as homeowner, senior, and disabled veteran, reduce EAV before taxes are calculated.
- Your tax bill is your parcel’s EAV after exemptions multiplied by the tax rate. The rate comes from local levies divided by total EAV across the taxing district.
How reassessment happens
General reassessment and updates
The assessor updates values using mass appraisal. Counties use periodic general reassessments and ongoing yearly maintenance. Timing and methods can change, so you should check Lake County’s current schedule and notices each year.
Triggers for value changes
- Market shifts reflected in recent comparable sales.
- Building permits, new construction, demolitions, and material condition changes.
- Annual maintenance where the assessor adjusts values even outside a full countywide reassessment.
Highland Park and Lake Forest context
When nearby homes sell higher or lower, those sale prices inform the models the assessor uses. If your neighborhood appreciates, you may see your assessed value increase in the next cycle or through maintenance updates. If conditions decline, the opposite can occur.
Appeal steps and timing
Start with your notice
When you receive an assessment notice, review the property characteristics and assessed value right away. Notices usually include instructions for next steps and filing windows.
Try an informal review first
Bring recent comparable sales, photos, and any corrections to the Lake County Assessor. Informal reviews are often quicker and can resolve many issues without a formal appeal.
File with the Board of Review
If you still disagree, submit a complaint to the Lake County Board of Review within the annual filing window. The Board schedules hearings and issues decisions based on your evidence and the assessor’s records.
PTAB and court options
If you remain unsatisfied after the Board of Review, appeal to PTAB. Judicial review through the Illinois circuit courts can follow PTAB decisions. Deadlines vary year to year, so always check the current filing calendar.
Building a strong case
- Use recent comparable sales near the January 1 valuation date and close to your home’s location.
- Provide photos that show condition, needed repairs, or differences from assessor records.
- Share building permits and documentation for additions, demolitions, or omitted improvements.
- Consider an independent appraisal for larger discrepancies. For income-producing properties, include income and expense data if relevant.
How assessments affect your bill
Lowering your assessed value reduces your share of the tax base, but it does not guarantee a lower bill. Local taxing bodies set annual levies, and the tax rate responds to levies and the total EAV in the district. If levies rise, a lower assessment might still lead to a similar or higher bill. There is also a timing lag. Changes in assessment typically flow into the next tax cycle after equalization and levy calculations.
What to check and gather
- Your latest assessment notice and the assessor’s property record card.
- A short list of nearby comparable sales close to the valuation date.
- Building permits, contractor invoices, or demolition records.
- Photos that document current condition and features.
- Any appraisal or broker price opinion you have available.
Where to verify and file
- Lake County Assessor for parcel data, exemptions, notices, and informal reviews.
- Lake County Board of Review for complaint forms, filing windows, and hearing procedures.
- Lake County Treasurer/Collector for billing and payment schedules.
- Lake County GIS/Property Search for maps, sales, and assessed values.
- Lake County Recorder of Deeds for recorded deeds and sales history.
- Illinois Department of Revenue for equalization policies and statewide guidance.
- Illinois Property Tax Appeal Board (PTAB) for state-level appeal procedures after local steps.
- The City of Highland Park and City of Lake Forest websites for local finance calendars and permit records.
Practical tips for North Shore owners
- Track nearby sales, especially for homes similar to yours, since these often shape reassessment outcomes.
- Check your property record card for errors in square footage, room count, or lot size. Clerical corrections are common and can be straightforward.
- Confirm that you have applied for all eligible exemptions and understand renewal requirements.
- Watch the Board of Review calendar. Missing the filing window usually forfeits an appeal for that tax year.
If you want a clear read on market value before you review your assessment or consider an appeal, get a local valuation and a curated set of comparable sales. With 25-plus years advising North Shore homeowners, we can help you understand where your home sits in today’s market and what that might mean for your next move.
Ready to get started? Connect with Kim Kelley Residential for a quick, data-informed valuation and local guidance.
FAQs
What is the valuation date for Illinois property taxes?
- Illinois uses January 1 as the valuation date for each tax year.
How often does Lake County reassess property?
- Lake County conducts periodic general reassessments plus ongoing annual maintenance. Check the Assessor’s current schedule each year.
Will appealing my assessment lower my tax bill?
- A successful appeal reduces your assessed value and EAV, which lowers your share of the levy. Your final bill still depends on levies and tax rates.
Where do I file a formal assessment complaint in Lake County?
- File with the Lake County Board of Review during its annual filing window and follow its procedures for evidence and hearings.
What if my Lake County property record has errors?
- Contact the Lake County Assessor for a correction or request an informal review. Many clerical issues can be resolved without a formal appeal.
Which exemptions can lower EAV for homeowners?
- Homeowner, senior, disabled veteran, and other exemptions can reduce EAV if you apply and meet county rules and deadlines.
