River Forest reassessment notices began mailing April 20. The south and west suburban townships are reassessed in 2026 on the standard triennial cycle. Each township opens for appeal one at a time, with roughly 30-day appeal windows. For district managers in the affected suburbs, the cycle resets the assessment base that drives BID and SSA revenue projections for the next three years.

For SSAs whose budgets are calibrated to the FY25 assessment base, the 2026 cycle requires re-projection of FY27 and FY28 revenue under the new base. Many SSAs will see a meaningful change in projected revenue, in either direction, depending on the township's aggregate assessment trend. The district managers who have not yet built the FY27 budget should not finalize it before their township's reassessment notice has been processed.

VISUAL: Cook County triennial reassessment cycle map showing 2026 township order with notice mail dates and appeal deadlines.

Watch

The order in which the south and west suburban townships open their appeal windows; the aggregate assessment trend by township.

Source

Cook County Assessor's Office, April 24, 2026.