Amends the Property Tax Code. Provides that, beginning in taxable year 2024, no taxing district, other than a home rule unit, may levy a tax on any parcel of real property that is more than 105% of the tax levied by that taxing district on that property in the immediately preceding taxable year unless (i) the increase is attributable to substantial improvements to the property, (ii) the taxing district did not levy a tax against the property in the previous taxable year, or (iii) the increase is attributable to a special service area. Provides that a taxing district may elect to be exempt from these provisions for one or more taxable years if the exemption is approved by referendum. Effective immediately.