1. 1. Any employee who became a member of the system, on the first day of the first month following the original effective date of sections 104.310 to 104.540, September 1, 1957, shall be given creditable prior service with the state. All such creditable prior service must be established to the satisfaction of the board.
2. 2. Any person who, on August 29, 1959, was an employee of the state government and a member of either the transportation department employees' and highway patrol retirement system or the Missouri state employees' retirement system and who, whether or not he became a member of either system on the original effective date of sections 104.310 to 104.540, September 1, 1957, had been since January 7, 1959, continuously in the employ of the state government in positions which would on August 29, 1959, have come under one or the other of the retirement systems, is entitled to credit for all of his prior service with the state whether it was as an employee of the transportation department, highway patrol or any other department as the term is defined in section 104.010.
3. 3. Any member of the system employed on or after August 13, 1988, and who served as an employee prior to September 1, 1957, but was not an employee on that date, shall be entitled to the creditable prior service that such employee would have been entitled to had such employee become a member of the retirement system on the date of its inception, if such employee has or attains one year of continuous membership service.

(L. 1984 H.B. 1370, A.L. 1988 H.B. 1643 & 1399)