Section 411.10A - Purchase of service credit for prior service1. An active member of the system who has been a member of the retirement system five or more years and who received a refund of the member's contributions for a prior period of service under the system may elect to purchase up to five years of service credit for that prior period of service, that will be recognized by the retirement system for purposes of calculating a member's benefit, pursuant to Internal Revenue Code section 415(n) and the requirements of this section.2.a. A member seeking to purchase service credit pursuant to this section shall file a written application with the system requesting an actuarial determination of the cost of a purchase of service credit. Upon receipt of the cost estimate for the purchase of service from the system, the member may make contributions to the system in an amount equal to the actuarial cost of the service credit purchase.b. For purposes of this subsection, the actuarial cost of the service credit purchase is an amount determined by the system in accordance with actuarial tables, as reported to the system by the system's actuary, which reflects the actuarial cost necessary to fund an increased retirement allowance resulting from the purchase of service credit.3. The system shall ensure that the member, in exercising an option provided in this section, does not exceed the amount of annual additions to a member's account permitted pursuant to section 415 of the federal Internal Revenue Code.4. The board of trustees shall adopt rules providing for the implementation and administration of this section.