(1) On and after July 1, 1974, hospitalization and medical coverage insurance premium payable by any retirant or his or her beneficiary and his or her dependents under any group health plan authorized by the Michigan civil service commission and the department of management and budget shall be paid by the retirement board from the health insurance reserve fund created in section 11. The amount payable shall be in the same proportion of premium payable by the state of Michigan for the classified employees occupying positions in the state civil service. The hospitalization and medical insurance premium payable shall be paid from appropriations made for this purpose to the health insurance reserve fund sufficient to cover the premium payment needed to be made.

    (2) Effective January 1, 1988, 90% of the premium payable by a retirant or the retirant's beneficiary and his or her dependents for dental coverage or vision coverage, or both, under any group plan authorized by the Michigan civil service commission and the department of management and budget shall be paid by the retirement board from the health insurance reserve fund created in section 11.

    (3) The department of management and budget shall calculate for each fiscal year any cost savings that have accrued to this state as a result of the implementation of 1996 PA 487 over the costs that would have been incurred by this state to fund premiums payable pursuant to section 68 had 1996 PA 487 not been implemented. The total amount of the cost savings, if any, shall be allocated to the health advance funding subaccount created under section 11(9).

    (4) On and after March 31, 1997, the retirement system shall also pay health insurance premiums described in this section in the manner prescribed in section 68.

    (5) For purposes of this section, "retirant" includes a person who retires under section 306 or 410 of the Michigan military act, 1967 PA 150, MCL 32.706 and 32.810.