35 ILCS 5/208
Tax credit for residential real property taxes. Beginning with tax years ending on or after December 31, 1991, every individual taxpayer shall be entitled to a tax credit equal to 5% of real property taxes paid by such taxpayer during the taxable year on the principal residence of the taxpayer. In the case of multi-unit or multi-use structures and farm dwellings, the taxes on the taxpayer's principal residence shall be that portion of the total taxes which is attributable to such principal residence. Notwithstanding any other provision of law, for taxable years beginning on or after January 1, 2017, no taxpayer may claim a credit under this Section if the taxpayer's adjusted gross income for the taxable year exceeds (i) $500,000, in the case of spouses filing a joint federal tax return, or (ii) $250,000, in the case of all other taxpayers.
35 ILCS 5/208