Medical necessity definitions are broad, and plans may adopt APA/AMA definitions, which are comparable across behavioral health and general medical care. Plans may also include in their definitions a consideration of costs (e.g., to provide efficient or cost-effective care). The panel view was that, broadly, medical necessity definitions that included cost-effectiveness considerations could be clinically appropriate.
Specific guidelines and criteria that plans adopt to guide medical necessity determinations are based on processes of expert review of existing guidelines, empirical literature, and other information. The panel discussed the types of information that might be relevant to the adoption of specific criteria: clinical efficacy, uncertainty, high potential costs, provider qualifications, practice variation. It could be reasonable to treat behavioral health conditions differently with respect to medical necessity determinations when the evidence base supports differences. The panel discussed specific examples, including fail-first and step-care requirements, and some types of procedures/services that are often considered unnecessary, to illustrate situations in which medical necessity determinations would or would not be clinically appropriate and meet parity requirements.