456.406—Description of UR review function: Who performs UR; disqualification from performing UR.
        
        (b) 
         UR must be performed using a method specified under  § 456.401(b) by a group of professional personnel that includes—
    
    
    
        
        (2) 
         In an ICF that cares primarily for mental patients, at least one individual knowledgeable in the treatment of mental diseases; and
    
    
        
        (3) 
         In an institution for the mentally retarded, a least one individual knowledgeable in the treatment of mental retardation.