<P> A national coverage determination (NCD) is a United States nationwide determination of whether Medicare will pay for an item or service . </P> <P> Medicare coverage is limited to items and services that are considered "reasonable and necessary" for the diagnosis or treatment of an illness or injury (and within the scope of a Medicare benefit category). </P> <P> In the absence of a NCD, an item or service is covered at the discretion of the Medicare contractors based on a Local Coverage Determination (LCD). </P> <P> NCDs can be requested by external parties who identify an item or service as a potential benefit (or to prevent potential harm) to Medicare beneficiaries . External parties who may request an NCD are Medicare beneficiaries, manufacturers, providers, suppliers, medical professional associations, or health plans . </P>

Who signed the national coverage determination (ncd) into law