(1) A school employee who became a member before July 1, 2014, and who has completed at least five years of creditable service plus eligibility and vesting credit or a school employee who became a member for the first time on or after July 1, 2014, and who has completed ten or more years of creditable service may purchase service credit for up to five years of creditable service. Such purchase may be executed up to twelve months prior to the employee’s retirement date. Such service credits shall be purchased by the employee for an amount equal to the actuarial cost to the retirement system for allowing such additional service credit to the employee.

(2) Payment for such service credits shall be completed prior to the employee’s termination of employment date and may be made through direct payment, installment payments, or an irrevocable deduction authorization. If payments are made on an installment basis, interest shall be charged at the rate of regular interest.

(3) Compensation for the period of service purchased shall not be included in determining the member’s final average compensation.

(4) The retirement board shall credit funds collected pursuant to this section to the Contingent Account pending the employee’s retirement. If the employee does not retire within twelve months after the execution of the purchase made pursuant to this section, such funds shall be refunded, excluding interest earned, and the employee shall not be given credit for the service credit attempted to be purchased.