(1) A qualified participant is immediately 100% vested in his or her contributions made to Tier 2. A qualified participant shall vest in the employer contributions made on his or her behalf to Tier 2 according to the following schedule:

    (a) Upon completion of 2 years of service, 50%.

    (b) Upon completion of 3 years of service, 75%.

    (c) Upon completion of 4 years of service, 100%.

    (2) A qualified participant is vested in the health insurance coverage provided in section 79 if the qualified participant meets 1 of the following requirements:

    (a) The qualified participant has completed 6 years of service as a qualified participant before January 1, 2013 and was not a member, deferred vested member, or former nonvested member of Tier 1.

    (b) The qualified participant was a member, deferred vested member, or former nonvested member of Tier 1 who made an election to participate in Tier 2 pursuant to section 61, and who has met the service requirements he or she would have been required to meet in order to vest in health benefits under section 50b.

    (c) The qualified participant meets all of the following requirements:

    (i) Was not a member, deferred vested member, or former nonvested member of Tier 1.

    (ii) Was first elected to fill a vacancy in the house of representatives for a period less than the full term but more than 1/2 of the term of office.

    (iii) Has completed 5 years of service as a qualified participant before January 1, 2013.