For purposes of this subpart-
Facility means an institution for mental diseases, or an intermediate care facility.
Intermediate care facility includes institutions for Individuals with Intellectual Disabilities or persons with related conditions but excludes religious nonmedical institutions as defined in § 440.170(b) of this chapter.
Institution for mental diseases includes a mental hospital, a psychiatric facility, and an intermediate care facility that primarily cares for mental patients.
Psychiatric facility includes a facility or program that provides inpatient psychiatric services for individuals under 21, as specified in § 441.151 of this chapter, but does not include psychiatric wards in acute care hospitals.
42 C.F.R. §456.601