S.C. Code § 9-9-65
2018 Act No. 221, Section 2.D, provides as follows:
"D. This SECTION takes effect upon approval by the Governor and applies to members who retire after December 31, 2016. A member whose one year deadline has expired or will expire in less than ninety days from the date of the Governor's approval has ninety days from the Governor's approval of this act to file an application for disability retirement."