O.C.G.A. § 47-1-84 (2019)

(a) Notwithstanding any other provision of this title to the contrary, the board of trustees of a retirement or pension system may modify a request by a plan member to make a contribution to the public retirement or pension system if the amount of the contribution would exceed the limits provided under Section 415 of the federal Internal Revenue Code by using the following methods:

(1) If the law requires a lump sum payment for the purchase of service credit, the board of trustees may establish a periodic payment plan for the plan member to avoid a contribution in excess of the limits under Section 415(c) or 415(n) of the federal Internal Revenue Code; and

(2) If the payment plan pursuant to paragraph (1) of this subsection will not avoid a contribution in excess of the limits, the board of trustees may refuse the plan member’s contribution.

(b) For any plan member who first became a plan member in the public retirement or pension system before January 1, 1998, the limitation of Section 415(c)(1) of the federal Internal Revenue Code shall not be applied to reduce the amount of permissive service credit which may be purchased to an amount less than the amount which was allowed to be purchased under state law on August 5, 1997.