S.C. Code § 9-1-1680
Except as provided in Section 9-18-10, and related sections, Article 11, Chapter 17, Title 63 and Section 8-1-115 and subject to the doctrine of constructive trust ex maleficio, and subject to income tax levies imposed pursuant to state or federal law and distributions made pursuant to the federal Pension Protection Act of 2006, the right of a person to an annuity or a retirement allowance or to the return of contributions, an annuity, or retirement allowance itself, any optional benefit, or any other right accrued or accruing to any person under the provisions of this chapter, and the monies of the system created under the provisions of this chapter or any private retirement system operated by a municipality, are exempted from any state or municipal tax, except the taxes imposed pursuant to Chapters 6 and 16 of Title 12, and exempted from levy and sale, garnishment, attachment, or any other process and are unassignable except as specifically otherwise provided in this chapter. This section does not apply to any authorized deduction from a retirement allowance.
S.C. Code § 9-1-1680