S.C. Code Ann. § 9-1-1910

A member with five or more years of earned service, eligible for service retirement, who has twenty or more years of creditable service must be paid from the general fund of the State, a monthly sum in addition to the retirement allowance due the member under this chapter sufficient to provide the member a minimum eighty dollars a month, plus one dollar a month for each completed year of creditable service in excess of twenty years. If the teacher or employee elects to receive a reduced retirement allowance as provided in this chapter, the teacher or employee must be paid under the provisions of this section only the amount as would be paid under the section had the teacher or employee not elected the optional allowance. Any person who retired prior to October 1, 1956, under the provisions of the South Carolina Retirement Act, while in service as such teacher or employee and who furnishes proper proof that he is not receiving primary Federal Social Security payments as a result of such employment, shall, effective July 1, 1969, be paid twenty-five dollars per month in addition to any payments otherwise payable under this section. Effective July 1, 1972, any person who has retired or may retire under the provisions of the South Carolina Retirement Act while in service as a teacher or employee, who has twenty or more years of creditable service and whose annual average final compensation is at least fifteen hundred dollars shall be paid from the South Carolina Retirement System a monthly sum, in addition to the retirement allowance he may receive under the act and any amount provided from the general fund of the State under the previous paragraphs, to provide a minimum of one hundred and fifty dollars per month, plus one dollar per month for each completed year of creditable service in excess of twenty years. If such person's effective date of retirement is on or after July 1, 1972, and he has not attained age sixty-five nor completed thirty-five years of creditable service at the time of his service retirement the gross minimum amount shall be reduced by five-twelfths of one per cent for each month by which his retirement date preceded the first day of the month coincident with or next following his sixty-fifth birthday. If such person's effective date of retirement is on or after July 1, 1972, and he retired on a deferred retirement allowance the amount payable at age sixty shall be seventy-five per cent of the gross minimum amount otherwise determined. Provided, however, that should such teacher or employee elect to receive a reduced retirement allowance as provided in the act, he shall be paid under the provisions of this section only such amount as would be paid under the section had he not elected such optional allowance. Provided, further, that the fifteen hundred dollars average final compensation required by this paragraph shall not apply to full-time lunchroom employees who retire no later than July 1, 1974.