S.C. Code Ann. § 9-1-1515
(A) In addition to other types of retirement provided by this chapter, a member may elect early retirement if the member:
(4) has separated from service.
A member electing early retirement shall apply in the manner provided in Section 9-1-1510.
(D)
(1) Except as provided in item (2) of this subsection, a member who elects early retirement under this section is not covered by the State Insurance Benefits Plan until the earlier of: