S.C. Code § 9-8-80
All retirement allowances are payable in monthly installments. Upon the death of a retired member, the retirement allowance for the month the retired member died, if not previously paid, must be paid to the member's spouse, or if the member designated a nonspouse beneficiary or beneficiaries, then to the nonspouse beneficiary or beneficiaries living at the time of the member's death, otherwise to the estate of the member. A spouse's entitlement to a benefit pursuant to Section 9-8-110 commences in the month after the retired member's death. If the retired member elected a survivor option pursuant to the optional retirement allowances in Section 9-8-70, any allowance payable to a survivor beneficiary or beneficiaries commences in the month after the death of the retired member.
S.C. Code § 9-8-80