Miss. Code Ann. § 41-30-23: Miss. Code Ann. § 41-30-23

The administrator in charge of any approved public or private in-patient, out-patient, or intermediate facility, subject to the rules and regulations established by the division, may determine who shall be admitted for treatment; provided no person shall be retained by the treatment facility upon voluntary commitment on an in-patient basis for a period in excess of thirty (30) days.