S.C. Code § 9-9-66
Once each year during the first five years following the retirement of a member on a disability retirement allowance and once in every three-year period thereafter the board may, and upon his application shall, require any disability beneficiary who has not yet attained the age of sixty years to undergo a medical examination, such examination to be made at the place of residence of such beneficiary or other place mutually agreed upon by physicians designated by the board. Should any disability beneficiary who has not yet attained the age of sixty years refuse to submit to at least one medical examination in any such year by a physician designated by the board his employer annuity may be discontinued until his withdrawal of such refusal and should his refusal continue for one year all his rights to his employer annuity may be revoked by the board.
S.C. Code § 9-9-66