National coverage determination (NCD)
means a decision that CMS makes regarding whether to cover a particular service on a national basis. An NCD does not include a determination of what code, if any, is assigned to a service or a determination with respect to the amount of payment to be made for the service-it merely decides the basis upon which Medicare will cover a particular service. In areas of fraud concern, NCD’s have been issued to clarify coverage conditions in order to avoid further fraud and abuse.