S.C. Code Regs. § § 19-905
In accordance with Section 9-1-470 and 9-1-860 of the Retirement Act the Budget and Control Board does hereby authorize the initial and collective employer contribution for previous service to be paid in a lump sum or in installments over such period, not to exceed ten years, as the Board may, under uniform rules, determine.
The State Budget and Control Board, acting in accordance with Section 9-1-440 and 9-1-860 of the South Carolina Code of Laws, as amended, hereby adopts an employee rate of four percent of his annual earnable rate of compensation, or four percent of the average of the three highest fiscal years of salary whichever is greater, at the time of payment, for each year of non-member service established and a proportionate part thereof for a portion of a year. The employer rate of contribution for non-member service shall be equal to the employee rate.
By administrative policy, the South Carolina Retirement System has interpreted Section 9-1-10, paragraphs 4 and 16, in a manner which precludes retirement credit when the payment for service rendered is only in the form of per diem. The granting of retirement credit for services rendered when the remuneration is limited to a per diem payment would impose a significant financial burden on the State; therefore, in accordance with Section 9-1-290 of the Retirement Act the Budget and Control Board hereby determines that services rendered which are remunerated solely by per diem shall not be considered creditable service for retirement purposes.
Credit will be allowed Clerks of Court and others for fees paid them by the public only in cases where the member is able to present a written record of such fees.
When compensation includes fees, the amount to be paid by the employee and matched by the employer shall be based upon the net fees and not the gross fees. Net fees means gross fees less necessary operating expenses and includes only those fees which the employee may lawfully retain (Section 9-1-10(16).
Under Section 9-1-10, S. C. Code 1976, earnable compensation includes maintenance and other things of value, etc. Where a teacher or employee's salary includes maintenance, the Board of Trustees or governing Board are authorized to evaluate such services in terms of dollars which shall be included as salary by the Retirement Board. This evaluation shall generally be subject to revision by the Retirement Board. The contribution shall be based on the sum of money and of the evaluation of maintenance where such maintenance is furnished by a State Agency or employer agency.
A member on sick leave without pay may establish up to 90 days if requested within 12 months of return to work. Contributions shall be based on salary immediately prior to the leave period.
S.C. Code Regs. § 19-905