(1) A member who has 12 or more years of credited service may elect to purchase not more than 2 years of service credit for active duty by filing a request with the retirement system. The member shall provide documentation of the active duty and shall pay into the reserve for member contributions an amount equal to 5% of the member’s annualized rate of compensation at the time payment is made multiplied by the number of years and months of active duty service that the member elects to purchase up to the maximum. The member shall relinquish for himself or herself and his or her beneficiaries all rights in and to a pension or annuity payable from another retirement system for the same period of service purchased under this section.

    (2) The retirement system shall calculate the amount of service credit for active duty under subsection (1) on the same basis as provided in section 402(1).