Cook County Value

9961 Rosemont Ave Rosemont, IL 60018

4 bed / 2 bath, 4,122 sqft, built 2004, in Leyden. Assessor market value for 2026: $870,000.

Cook County account 12042060500000

Assessor market value
$870,000
Tax year 2026 · before exemptions; the assessed value on your notice is 10% of it
Living area
4,122 sqft
$211 per sqft
Year built
2004
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 60018 and Leyden assessment pages.

Local guide: Leyden Township 2026 Property Tax Appeal Guide.

Appeal deadlines

For Leyden, appeals to the Assessor closed . Board of Review dates for Leyden 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 stayed about the same, from $870,000 in 2025 to $870,000 in 2026.
  • Assessor market value per square footThe current public record shows about $211 per square foot before any comparable-property adjustments.
  • Nearby comparison areaThis page starts the equity review with public records for the Leyden neighborhood and ZIP 60018.
  • Neighborhood value signalAmong 503 residential records in the same neighborhood, the average assessor market value is about $240 per square foot.
  • Area year-over-year signalNearby residential records with prior-year values moved about -1.8% on average.

Comparable assessments

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

  • 6027 Scott St Rosemont, IL 60018
    4,251 sqft | $219/sqft | built 2003 | Similar size (4,251 vs 4,122 sqft); Similar age (2003 vs 2004); Lot 10% larger (5,753 vs 5,225 sqft)
    $930,000
  • 6117 Byron St Rosemont, IL 60018
    3,275 sqft | $245/sqft | built 2007 | Similar age (2007 vs 2004); Similar lot size (5,441 vs 5,225 sqft); Same quality (Average)
    $803,130
  • 6217 N Hawthorne St Rosemont, IL 60018
    4,243 sqft | $106/sqft | built 2006 | Similar size (4,243 vs 4,122 sqft); Similar age (2006 vs 2004); Same quality (Average)
    $450,290
  • 6217 N Hawthorne St Rosemont, IL 60018
    4,243 sqft | $106/sqft | built 2006 | Similar size (4,243 vs 4,122 sqft); Similar age (2006 vs 2004); Same quality (Average)
    $450,290
  • 6021 Byron St Rosemont, IL 60018
    3,831 sqft | $223/sqft | built 2006 | 7% smaller (3,831 vs 4,122 sqft); Similar age (2006 vs 2004); Same quality (Average)
    $853,550

Recent comparable sales

No usable comparable sales are available in this data snapshot.

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

No change in 2026 from 2025.

Assessor market value by tax year, with the change from the previous year listed
Tax yearAssessor market valueChangeChange %
2026$870,000$00.0%
2025$870,000+$214,890+32.8%
2024$655,110−$44,890−6.4%
2023$700,000$00.0%
2022$700,000+$170,130+32.1%
2021$529,870+$100.0%
2020$529,860——
6-year total+$340,140+64.2%