S.C. Code § 9-9-110
If a retired member returns to service as a member of the General Assembly, the retired member may elect to become a contributing member of the System or may elect to remain a retiree and continue to receive a retirement benefit. The election pursuant to this paragraph is irrevocable and applies for as long as that person serves thereafter in the General Assembly, including service in both regular and extra sessions.
If a retired member returning to serve as a member of the General Assembly elects to become a contributing member, the retired member must be credited with all service standing to the retired member's credit at the time of retirement and the retirement allowance payable upon the person's subsequent retirement must be based on the total of the person's credited service rendered before and after return to service.
If a retired member returning to serve as a member of the General Assembly elects to remain a retiree, the retired member may continue to receive a retirement benefit while serving in the General Assembly. A retired member returning to service in the General Assembly who elects to continue to receive a retirement benefit pursuant to this paragraph shall make no further contributions to the system, shall earn no further service credit, may not reenter membership in the system, and has elected to receive a retirement allowance in lieu of receiving the constitutionally mandated per diem salary, currently established at ten thousand four hundred dollars for a regular session.
Notwithstanding any other provision of law, if a retired member returns to service in a position other than as a member of the General Assembly that is covered by the South Carolina Retirement System, the Police Officers Retirement System, or the Retirement System for Judges and Solicitors, the member is subject to the same earnings limitation as under the South Carolina Retirement System.
S.C. Code § 9-9-110