(a) Active and contributing members of the Teachers' Retirement System (TRS) or the Employees' Retirement System (ERS) may claim and purchase service credit in the system not to exceed eight years for any period of prior service while they were full-time employees of an employer who is authorized to join the TRS pursuant to Section 16-25-10.7, but has not elected to participate. The certification of any prior service claimed by the members under this section shall conform to applicable administrative rules and procedures of the TRS or ERS. Members shall receive credit for the prior service when they remit to the system the contributions required by subsection (b). Notwithstanding the foregoing, no member of the system shall receive credit for any service that the member is already credited with in the system or 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 TRS or ERS under subsection (a) shall pay to the Secretary-Treasurer of the system, within one year from September 1, 1999, for the claimed service, a sum equal to the full actuarially required cost for each year of service credit purchased as determined by the actuary for the system.