Cook County Value

12864 Mayfair Dr Lemont, IL 60439

4 bed / 3 bath, 3,513 sqft, built 2005, in Lemont. Assessor market value for 2026: $840,000.

Cook County account 22312060120000

Assessor market value
$840,000
Tax year 2026 · before exemptions; the assessed value on your notice is 10% of it
Living area
3,513 sqft
$239 per sqft
Year built
2005
Average quality

Compare this assessment

Start with the county value and property facts, then review appraisal comps, recent sales, and prior-year changes to decide whether the assessment is worth challenging. The comps on this page are free to review; email sign-in is only used to save a printable report.

For nearby context, browse ZIP 60439 and Lemont assessment pages.

Local guide: Lemont Township 2026 Property Tax Appeal Guide.

Appeal deadlines

For Lemont, appeals to the Assessor closed . Board of Review dates for Lemont have not been published yet.

Deadline rule: Set by township: file with the Assessor by your township's last file date, and with the Board of Review while your township is open there. Evidence is reviewed by the Cook County Assessor's Office or, in a separate appeal, by the Cook County Board of Review. Dates checked against the official source.

Assessment snapshot

These public CCAO records highlight what may be worth checking before you file.

  • Assessment changeThe assessor market value increased 18.3% from $710,000 in 2025 to $840,000 in 2026.
  • Assessor market value per square footThe current public record shows about $239 per square foot before any comparable-property adjustments.
  • Nearby comparison areaThis page starts the equity review with public records for the Lemont neighborhood and ZIP 60439.
  • Neighborhood value signalAmong 2,806 residential records in the same neighborhood, the average assessor market value is about $255 per square foot.
  • Area year-over-year signalNearby residential records with prior-year values moved about +30.4% on average.

Comparable assessments

Showing 5 of the 8 similar homes in this property's equity comparison, from public appraisal records.

  • 409 Fourth St Lemont, IL 60439
    3,510 sqft | $265/sqft | built 2001 | Similar size (3,510 vs 3,513 sqft); Similar age (2001 vs 2005); Similar lot size (20,069 vs 19,802 sqft)
    $930,010
  • 13000 Ravine Dr Lemont, IL 60439
    3,512 sqft | $245/sqft | built 1998 | Similar size (3,512 vs 3,513 sqft); Similar lot size (20,516 vs 19,802 sqft); Same quality (Average)
    $860,000
  • 13068 Ravine Dr Lemont, IL 60439
    3,497 sqft | $246/sqft | built 1998 | Similar size (3,497 vs 3,513 sqft); Similar lot size (18,643 vs 19,802 sqft); Same quality (Average)
    $860,000
  • 77 Deer Ln Lemont, IL 60439
    3,530 sqft | $313/sqft | built 2003 | Similar size (3,530 vs 3,513 sqft); Similar age (2003 vs 2005); Similar lot size (20,507 vs 19,802 sqft)
    $1,105,000
  • 13018 Spruce Hill Ct Lemont, IL 60439
    3,465 sqft | $251/sqft | built 2001 | Similar size (3,465 vs 3,513 sqft); Similar age (2001 vs 2005); Similar lot size (19,035 vs 19,802 sqft)
    $870,000

Recent comparable sales

Sales selected by similarity to the subject property.

  • 12554 Eileen St Lemont, IL 60439
    June-29-2026 | 3,421 sqft | $272/sqft | built 2025 | Similar size (3,421 sqft); Sold after the valuation date; Within 1 bedroom (5 vs 4)
    $930,895
  • 12655 Derry Dr Lemont, IL 60439
    June-29-2026 | 2,672 sqft | $266/sqft | built 2025 | Sold after the valuation date; Within 1 bedroom (3 vs 4)
    $710,150

Public appraisal comparison for 2026. Prepared . Appraisal source: Cook County Assessor's Office. Sales data checked in this snapshot: . Matches consider available size, age, location and property characteristics. How comparisons work.

Value history

Up 18.3% in 2026 from 2025.

Assessor market value by tax year, with the change from the previous year listed
Tax yearAssessor market valueChangeChange %
2026$840,000+$130,000+18.3%
2025$710,000$00.0%
2024$710,000$00.0%
2023$710,000+$158,460+28.7%
2022$551,540$00.0%
2021$551,540$00.0%
2020$551,540——
6-year total+$288,460+52.3%