(1) A legislator who did not elect to continue to participate in the system, as provided under 5-2-304, and who subsequently participates as a member must be awarded creditable service for legislative service if the legislator contributes an amount equal to the member contributions that would have been made if the legislator had elected membership plus interest paid as follows:
(a) if a written application to purchase service was signed prior to July 1, 2012, at the rate that the contributions would have earned if they had been on deposit with the retirement system; or
(b) if a written application to purchase service is signed on or after July 1, 2012, at the actuarially assumed interest rate in effect on the date the written application is signed.
(2) The employer contribution must be made by the legislative branch in the amount that would have been contributed if the legislator had elected membership plus interest at the rate that the contributions would have earned if they had been on deposit with the retirement system.