LCD vs NCD
An NCD (National Coverage Determination) is CMS's nationwide Medicare coverage policy; an LCD (Local Coverage Determination) is a Medicare Administrative Contractor's policy for its own jurisdiction, used where no NCD controls. NCDs always outrank LCDs. Since 2019, the billable CPT/ICD-10 code lists live in companion billing and coding articles, not the LCD itself.
- NCD
- National, issued by CMS, binds all MACs
- LCD
- Jurisdiction-level, issued by each MAC
- Hierarchy
- NCD overrides LCD, always
- Code lists
- Now in billing & coding articles (A-articles)
What is the difference between an LCD and an NCD?
Both answer the same question, whether Medicare considers a service reasonable and necessary, at different altitudes. An NCD is issued by CMS and binds every Medicare Administrative Contractor nationwide; there are a few hundred of them covering topics like screening colonoscopy frequency and implantable defibrillators. An LCD is issued by an individual MAC for its own multi-state jurisdiction and fills the enormous space NCDs never address: most lab tests, injections, imaging indications, wound care, and so on.
The hierarchy is strict: NCD first, LCD second, and MAC discretion (articles, claim-by-claim review) third. For billers this means one thing daily: the coverage rules behind a CO-50 denial are almost always in an LCD and its article, and they are specific to your MAC.
Where do the billable codes actually live now?
Not in the LCD. Since 2019, MACs publish the CPT/HCPCS and ICD-10 lists in companion billing and coding articles (IDs starting with "A"), linked from the LCD (IDs starting with "L"). The LCD itself reads like a clinical policy paper; the article is the operational document your scrubber cares about. Teams that only read the LCD routinely conclude "coverage looks fine" while the article's diagnosis list quietly excludes the code they are billing.
Worked example: a practice bills 82306 (vitamin D, roughly $27 allowed) under a MAC whose article lists osteoporosis, chronic kidney disease, and malabsorption among covered indications, but not generalized fatigue. Ten fatigue-coded tests a month is $270 in structural denials; the fix is order-entry indication capture, not appeals. This is medical necessity plumbing at its most literal.
How do you use the Medicare Coverage Database well?
- Search the CPT code in the Medicare Coverage Database, filtered to your state or MAC.
- Open the billing and coding article first; verify the ICD-10 list, frequency limits, and documentation requirements.
- Check the LCD's revision history and effective dates, since retired or revised policies explain sudden denial spikes on codes that "always paid before."
- For NCD topics, read the NCD and the related MLN transmittal; frequency rules like screening intervals hide there.
Two habits pay off. First, subscribe to your MAC's LCD update mailing list; proposed LCDs have public comment windows, and finalized changes land with effective dates your scrubber needs before day one. Second, when a Medicare Advantage plan denies something traditional Medicare covers, cite the specific NCD/LCD in your appeal; MA plans must follow them as a coverage floor.
Frequently asked questions
The NCD, always. MACs may develop LCDs only where no NCD exists or where an NCD leaves gaps to interpret. If CMS issues an NCD on a topic, conflicting local policy is void. In practice most day-to-day lab, imaging, and procedure coverage questions are LCD territory because NCDs cover a relatively short list of topics.
Because coverage is set by LCDs where no NCD exists, and each Medicare Administrative Contractor writes its own. A molecular pathology test may have a generous covered-diagnosis list under one MAC and a restrictive one under another. Multi-state groups must check the LCD for the jurisdiction where the service was furnished.
Into companion billing and coding articles. CMS required MACs to strip CPT/HCPCS and ICD-10 code lists out of LCDs starting in 2019, leaving the LCD as the clinical "reasonable and necessary" narrative. When checking coverage, open the article linked from the LCD; that is where the payable diagnosis codes actually are.
Yes as a floor. MA plans must cover services in accordance with NCDs and the LCDs of the jurisdiction, and CMS rules finalized in 2023 restrict plans from using proprietary criteria to deny what traditional Medicare would cover. MA plans can still add prior authorization on top, which is where most friction happens.
Sources & further reading
Reviewed by the ImmediCare Solutions RCM team
Certified billers and coders handling claims across 50+ specialties nationwide. This entry is reviewed against current payer policy and CMS rules. Last review: Jul 5, 2026.
Stop losing revenue to problems like this.
A free billing audit shows exactly where your practice is leaking money — no cost, no commitment.
