S.C. Code Ann. § 16-1-120
(1) When an individual, who was convicted of a Class A, B, or C felony offense or an exempt offense which provides for a maximum term of imprisonment of twenty years or more and sentenced to a period of time, has been released from prison, whether on parole or by completion of the sentence, is convicted of another felony offense, the individual shall have added to the sentence imposed for the subsequent conviction such additional time as provided below: