Synopsis As Introduced Amends the Property Tax Code. Provides for a reduction in the equalized assessed value of newly-constructed or rehabilitated rental property if the owner of the residential real property commits that, for a period of 10 years, at least 15% of the multifamily building's units will have rents that are at or below maximum rents and are occupied by households with household incomes at or below maximum income limits. Provides that the chief county assessment officer of a county with 3,000,000 or more inhabitants shall establish such a program, and the chief county assessment officer of a county with less than 3,000,000 inhabitants shall establish such a program upon passage of an ordinance by a majority vote of the county board. Sets forth application requirements and the amount of the reduction. Effective immediately.