42 CFR §447.40

1. (a)The Medicaid agency may make payments to reserve a bed during a beneficiary's temporary absence from an inpatient facility, if—
   1. (1)The State plan provides for such payments and specifies any limitations on the policy; and
   2. (2)Absences for purposes other than required hospitalization (which cannot be anticipated and planned) are included in the patient's plan of care.
2. (b)An agency that pays for reserved beds in an inpatient facility may pay less for a reserved bed than an occupied bed if there is a cost differential between the two beds. (Section 1102 of the Act.)