(a) Any provisions of Chapter 25 of this title, to the contrary notwithstanding, active and contributing members of the Teachers' Retirement System may purchase service credit in the system not to exceed one year for any period of time that they were required to be on leave from service without pay to comply with any state adoption law or regulation requiring a prospective adopting parent to stay home from work until the adoption process was finalized. The Board of Control of the Teachers' Retirement System shall adopt rules and regulations for the administration of this section including verification of the service that the member desires to purchase credit for in the system. The member shall receive credit for the service when he or she remits to the system the contributions required by subsection (b). Notwithstanding the foregoing language, no member of the Teachers' Retirement System shall be eligible to receive credit for any service that the member is already credited with in the system or in any other public retirement plan, with the exception of the federal Social Security program.

(b) Any member who is eligible to purchase service credit in the Teachers' Retirement System under subsection (a) shall pay to the Secretary-Treasurer of the system, within one year from October 1, 1993, for the claimed service, a sum equal to a percentage of his or her current annual earnable compensation or the average of his or her annual compensation for the two scholastic years immediately prior to the purchase, whichever is greater. The applicable percentage shall be the sum of the prevailing percentage rates of employer and member contributions, as required by the most recent actuarial valuations, for each year of service credit purchased.