Question: What’s the difference between a national coverage determination (NCD) and a local coverage determination (LCD), besides the obvious difference in scope? Nevada Subscriber Answer: One big difference between NCDs and LCDs is the way that they’re developed. According to the Centers for Medicare & Medicaid Services (CMS), LCDs are developed by Medicare Administrative Contractors (MACs), and NCDs are established by CMS. In its Medicare Coverage Type Descriptions document, CMS says LCDs are decisions made by MACs “on whether a particular service or item is reasonable and necessary, and therefore covered by Medicare within the specific jurisdiction that the MAC oversees. … LCDs outline how the contractor will review claims to ensure that the services provided meet Medicare coverage requirements. Before an LCD becomes final, the MAC publishes Proposed LCDs, which include a public comment period.” MACs develop LCDs for a topic or service in the absence of an NCD. CMS describes NCDs as national policies developed and released by CMS establishing the Medicare coverage for specific medical items or services across all states. MACs are required to follow NCDs, and NCDs trump LCDs. Check out the CMS website for more information about different Medicare coverage types.