Prior service credits in the Public Employees' Retirement System of Mississippi may be granted only for service performed for a State Agency, or for an instrumentality or juristic entity of the State of Mississippi, which is covered by an agreement executed between such instrumentality or juristic entity and the Public Employees' Retirement System of Mississippi and which includes Article II of the agreement, in accordance with the provisions of SB 273, Laws of 1952 (now Article III beginning at Miss. Code. Ann. § 25-11-101 et seq. (1972, as amended).
27 Miss. Code. R. 210-09-101