This State Plan Amendment adjusts base per diem rates for Psychiatric Residential Treatment Facility (PRTF) services rendered to persons under age 21 as follows: PRTFs will be reimbursed at provider-specific prospective rates based on the SFY 2020 or more recently available cost reports, including a 5% inflation factor and removing a cost cap provision. The per diem rate for children with a co-occurring diagnosis of autism will be at prospective rates based on 2020 or more recently available cost reports specific to service delivery of children with co-occurring diagnoses.