(1) By a 2/3 vote of its governing body each year, prior to the beginning of the medical benefit plan coverage year, a local unit of government may exempt itself from the requirements of this act for the next succeeding medical benefit plan coverage year.

    (2) A 2/3 vote of the governing body of the local unit of government prior to the beginning of each succeeding medical benefit plan coverage year is required to extend an exemption under this section.

    (3) An exemption under this section is not effective for a city with a mayor who is both the chief executive and chief administrator, unless the mayor also approves the exemption.

    (4) An exemption under this section is not effective for a county with a county executive who is both the chief executive and chief administrator, unless the county executive also approves the exemption.

    (5) An exemption under this section is not effective for a city with a population greater than 600,000.