Michigan Compiled Laws, Chapter 211. Taxation of Real and Personal Property § 211.89

(a) To the extent not waived pursuant to section 59(3), there shall be added to all delinquent taxes unpaid after March 1, interest at the rate of 1.25% per month or fraction of a month from the date the taxes originally become delinquent pursuant to this act, together with a county property tax administration fee equal to 4% of the delinquent taxes or $2.00 per payment of delinquent taxes, whichever is greater, which amounts shall be paid to the county treasurer.

(b) In addition to the expenses specified in section 59, delinquent tax sales shall include a county property tax administration fee equal to 4% of the delinquent taxes, and interest computed at a rate of 1.5% per month from the date the taxes originally become delinquent under this act.

(c) The rate of interest to be paid to the treasurer under section 74 shall be computed at the rate of 1.5% per month or fraction of a month.

(d) The rate of interest to be paid to the department of treasury pursuant to section 84  2 shall be computed at the rate of 1.5% per month or fraction of a month.

(a) In counties with a population of more than 1,500,000, it shall apply immediately except that it shall not apply to any delinquent taxes that became delinquent before March 1, 1981, or which become delinquent after February 28, 1983.

(b) In all other counties of this state it shall apply only to the 1981 delinquent taxes that become delinquent on or before March 1, 1982.