Miss. Code Ann. § 25-11-315: Miss. Code Ann. § 25-11-315

(1) Any member of the State Legislature or the President of the Senate who becomes a member of the plan on July 1, 1989, shall be eligible for prior service as a member of the State Legislature or as President of the Senate. Each member shall submit to the board a verification of prior service as a member of the State Legislature or as President of the Senate. Upon receipt of that prior service statement, the board shall issue a prior service certificate certifying to each member the length of prior service for which credit has been allowed on the basis of the statement of service. Additional prior service regulations in force shall be those found in Section 25-11-101 et seq.

(2)(a) Any member of the State Legislature or the President of the Senate who becomes a member of this plan after July 1, 1989, but before July 1, 2007, shall not be allowed prior service unless the member serves as a member of the State Legislature or as President of the Senate for a minimum of four (4) years and contributes to the plan for a minimum period of four (4) years.

(b) Any member of the State Legislature or the President of the Senate who becomes a member of this plan on or after July 1, 2007, shall not be allowed prior service unless the member serves as a member of the State Legislature or as President of the Senate for a minimum of eight (8) years and contributes to the plan for a minimum period of eight (8) years.