Mich. Comp. Laws § 208.1422

Sec. 422. (1) Subject to subsection (2), a taxpayer that makes charitable contributions of $50,000.00 or more during the tax year to either of the following may claim a credit against the tax imposed by this act equal to 50% of the amount by which the aggregate amount of the charitable contributions to either of the following exceeds $50,000.00: (a) A municipality or a nonprofit corporation affiliated with a municipality and an art, historical, or zoological institute for the purpose of benefiting the art, historical, or zoological institute. (b) An institution devoted to the procurement, care, study, and display of objects of lasting interest or value. (2) The credit allowed under this section for any tax year shall not exceed $100,000.00. (3) If the amount of the credit allowed under this section exceeds the tax liability of the taxpayer for the tax year, that portion of the credit that exceeds the tax liability shall not be refunded.