(a) As used in this Code section, the term:

(1) "Board of trustees" means the board of trustees or other fiscal authority or governing body, by whatever name designated, of a retirement system.

(2) "Retirement system" means a retirement or pension system or fund created by or pursuant to the authority of Georgia law which was listed in paragraph (4) of subsection (a) of Code Section 48-7-27 on January 1, 1989.

(b) The board of trustees of a retirement system is authorized to increase benefits paid to both present and future retirees and beneficiaries under the retirement system to offset, wholly or partially, the taxation of retirement benefits pursuant to the provisions of Chapter 7 of Title 48, relating to Georgia income taxes, provided that any increase in benefits granted pursuant to the authority of this subsection:

(1) Shall not apply to any portion of a benefit which exceeds $37,500.00 on the date the benefit increase is granted; and

(2) Shall be consistent with maintaining the actuarial soundness of the retirement system in conformity with minimum funding requirements of Code Section 47-20-10.

(c) The provisions of this Code section are in addition to any powers possessed by a board of trustees pursuant to the provisions of any other law.