S.C. Code Ann. § 9-8-50
(1) The credited service of a member shall include all service as a judge or solicitor since he last became a member of the System and in respect of which he makes contributions to the System. It shall also include, in the case of a member of the System who remained a member continuously until his death or his retirement under the System, service which he was, or would be, entitled to claim as creditable service under any other retirement system of the State of South Carolina, notwithstanding that he may not have been a member of such retirement system if, within twelve months of the date he becomes a member of the System, the full amount of his contributions required to be made under the other system in respect of such service shall be paid to this System by transfer or otherwise. Such amount shall not be less than the amount that the member would have contributed with respect to his position had he been a member of this System for the same period of time, plus interest.
On or after July 1, 1980, the Board may determine the contributions required by this section but it shall not be less than four percent of the annual compensation of the position at the time of payment for each year of service.