Ariz. Admin. Code § 9-31-701
Definitions. The words and phrases in this Article have the following meanings unless the context explicitly requires another meaning:
"Covered charges" means billed charges that represent medically necessary, reasonable, and customary items of expense for Title XXI-covered services that meet medical review criteria of the Administration or contractor.
"Medical review" means a review involving clinical judgment of a claim or a request for a service before or after it is paid or rendered to ensure that the services provided to the member are medically necessary and covered services and that the provider obtains required authorizations. The criteria for medical review are established by the contractor based on medical practice standards that are updated periodically to reflect changes in medical care.
"Outlier" means a hospital claim or encounter in which the Title XXI inpatient hospital days of care have operating costs per day that meet the criteria in A.A.C. R9-22-712.
"Tiered per diem" means a payment structure in which payment is made on a per-day basis depending upon the tier into which the Title XXI inpatient hospital day of care is assigned.
Ariz. Admin. Code § R9-31-701