S.C. Code Ann. § 44-20-400

Upon the written request of the person, the person's parents, parent with legal custody, or lawful custodian or legal guardian and subject to the availability of suitable accommodations and services, a person with intellectual disability, a related disability, head injury, or spinal cord injury may be admitted to the services of the office for evaluation and diagnosis and shall remain in the residential services of the office for that period required to complete the diagnostic study. However, this period may not exceed thirty days except upon approval of the office director or his designee. Individuals admitted under the provisions of this section are subject to the same regulations and office policies as regular admissions. The office may prescribe the form of the written application for diagnostic services.