Mich. Comp. Laws § 16
The state, in addition to any other borrowing power, may borrow from time to time such amounts as shall be required, pledge its faith and credit and issue its notes or bonds therefor, for the purpose of making loans to school districts as provided in this section.
If the minimum amount which would otherwise be necessary for a school district to levy in any year to pay principal and interest on its qualified bonds, including any necessary allowances for estimated tax delinquencies, exceeds 13 mills on each dollar of its assessed valuation as finally equalized, or such lower millage as the legislature may prescribe, then the school district may elect to borrow all or any part of the excess from the state. In that event the state shall lend the excess amount to the school district for the payment of principal and interest. If for any reason any school district will be or is unable to pay the principal and interest on its qualified bonds when due, then the school district shall borrow and the state shall lend to it an amount sufficient to enable the school district to make the payment.
The term "qualified bonds" means general obligation bonds of school districts issued for capital expenditures, including refunding bonds, issued prior to May 4, 1955, or issued thereafter and qualified as provided by law pursuant to Section 27 or Section 28 of Article X of the Constitution of 1908 or pursuant to this section.
After a school district has received loans from the state, each year thereafter it shall levy for debt service, exclusive of levies for nonqualified bonds, not less than 13 mills or such lower millage as the legislature may prescribe, until the amount loaned has been repaid, and any tax collections therefrom in any year over and above the minimum requirements for principal and interest on qualified bonds shall be used toward the repayment of state loans. In any year when such levy would produce an amount in excess of the requirements and the amount due to the state, the levy may be reduced by the amount of the excess.
Subject to the foregoing provisions, the legislature shall have the power to prescribe and to limit the procedure, terms and conditions for the qualification of bonds, for obtaining and making state loans, and for the repayment of loans.
The power to tax for the payment of principal and interest on bonds hereafter issued which are the general obligations of any school district, including refunding bonds, and for repayment of any state loans made to school districts, shall be without limitation as to rate or amount.
All rights acquired under Sections 27 and 28 of Article X of the Constitution of 1908, by holders of bonds heretofore issued, and all obligations assumed by the state or any school district under these sections, shall remain unimpaired.
MCL 16