A Medicare patient receives a service covered under a National Coverage Determination, and the regional MAC also publishes an LCD with additional coverage details for the same service. How should the physician coder apply these sources?

National Coverage Determinations establish Medicare coverage policy nationwide. Medicare Administrative Contractor Local Coverage Determinations and related articles add jurisdiction-specific coverage criteria that operate within national policy. When a Medicare patient receives a service addressed by both an NCD and a regional MAC LCD, the physician coder applies the NCD’s national coverage framework together with the MAC LCD’s local coverage details as they apply to the professional claim—not one source in isolation. Letting the LCD supersede the NCD when they differ is wrong because national policy remains the controlling framework, and an LCD cannot simply erase an NCD. Applying only the LCD and treating NCDs as optional educational material is wrong because it undervalues national coverage status. Following commercial payer policy instead of either Medicare coverage document is wrong when the claim is traditional Medicare Part B. Exam caveat: confirm MAC jurisdiction, NCD/LCD effective dates, and any billing or coding articles linked to the LCD before finalizing coverage-sensitive clinic procedures. Operational check: look up the NCD for national coverage status, open the applicable MAC LCD or article for local indications and diagnosis expectations, align ICD-10-CM pointers and documentation, and retain both citations in the county Medicare coverage file.