Michigan Compiled Laws, Chapter 205. Taxation § 205.913

Sec. 13.  (1) Except as otherwise provided under subsection (2), the revenue collected under this act must be deposited in the following manner:

(2) For the 2027-2028 state fiscal year and each fiscal year thereafter, the state treasurer shall adjust the amount to be deposited to the comprehensive road funding fund under subsection (1)(b) for inflation, as measured by the ratio of the average published monthly Consumer Price Index values for the previous fiscal year to the published monthly Consumer Price Index values for the fiscal year prior to the previous fiscal year, minus 1.  If the calculated change in the Consumer Price Index is negative, the adjustment for that fiscal year is zero.  As used in this subsection, “Consumer Price Index” means the most comprehensive index of consumer prices available for this state from the Bureau of Labor Statistics of the United States Department of Labor.