S.C. Code Ann. § 44-61-50

A vehicle must not be operated as an ambulance, unless its licensed owner applies for and receives an ambulance permit issued by the department for that vehicle. Prior to issuing an original permit for an ambulance, the vehicle for which the permit is issued shall meet all requirements as to vehicle design, construction, staffing, medical and communication equipment and supplies, and sanitation as set forth in this article or in the standards and regulations promulgated by the board. Absent revocation or suspension, permits issued for ambulances are valid for a period not to exceed two years.