(1) On or after January 1, 1997, any employee who is on leave of absence from an institution in order to serve as a state legislator may elect to continue to participate in any annuity or retirement plan authorized under RCW 28B.10.400 during the period of such leave.

(2) The institution shall pay the employee's salary attributable to legislative service and shall match the employee's retirement plan contributions based on the salary for the leave period. The state legislature shall reimburse the institution for the salary and employer contributions covering the leave period.

(3) "Institution" for purposes of this section means any institution or entity authorized to provide retirement benefits under RCW 28B.10.400.