Illinois Property Tax Stability Act Caps Increases for Rockford Homeowners

The Illinois General Assembly passed Senate Bill 1847, the Property Tax Stability Act, last month. The measure applies directly to Rockford residents who own single-family homes and small multifamily buildings assessed by Winnebago County.

Local property taxes fund city services, township roads, and Rockford School District 205 operations. Assessments rose 11 percent countywide between 2024 and 2025, pushing many Rockford households above the prior statutory cap that expired in 2025.

Daily costs for Rockford households

Under the new law, any increase in a property’s equalized assessed value that would push the tax bill higher than 3 percent must be offset by a corresponding reduction in the local tax rate. The legislation states that the cap covers the primary residence plus one additional parcel owned by the same taxpayer within the county.

A Rockford homeowner whose 2026 tax bill totaled $4,150 would see the 2027 bill capped at $4,274.50 before any new levies. The Winnebago County Clerk’s office projects that 68,400 parcels inside Rockford city limits fall under the cap. Local advocates note the change removes the need for annual appeals in many cases where assessments outpace income growth.

Implementation steps ahead

County assessors must recalculate rates by March 2027 and mail revised notices by April. The Rockford Township Board will hold a required public hearing on the adjusted levy in May. The government says the policy will reduce the number of protested assessments filed with the county by roughly 2,200 cases each year.

Residents who added improvements valued above $25,000 after 2025 remain subject to full reassessment on the added value only. The statute excludes commercial and industrial parcels, which continue under the prior system. The first bills reflecting the cap reach mailboxes in June 2027.