An NCD (National Coverage Determination) is a CMS decision on whether Medicare covers a service nationwide. An LCD (Local Coverage Determination) is a decision by your Medicare Administrative Contractor (MAC) on whether a service is covered in its jurisdiction. When both exist for the same service, the NCD sets the national rule and the LCD can only add local detail that does not conflict with it. Your claim still has to satisfy both.
This guide explains the difference in plain terms, shows you how to look up the right policy for a CPT or HCPCS code, and covers the documentation habits that keep claims from denying.
TL;DR
- NCD: issued by CMS, applies nationally, and is binding on the Medicare contractors and adjudicators that review claims.
- LCD: issued by a MAC, applies only within that contractor's jurisdiction, and may fill gaps or add detail where no NCD exists.
- Conflicts: an LCD can supplement an NCD only if it does not conflict with national policy.
- Practice impact: the LCD is often what your claim edits actually check, so you need to know both policies for the services you bill.
- Where to look: the Medicare Coverage Database (MCD) holds both, along with the MAC articles that list the codes.
Table of Contents
- What an NCD is
- What an LCD is
- LCD vs NCD side by side
- Which one controls?
- How to look up an LCD or NCD by CPT code
- What to verify before you submit a Medicare claim
- A worked example
- Where LCD and NCD problems hide in a practice
- Our perspective
- Find out what policy gaps are costing you
- What to do when your practice disagrees with an LCD
- A short routine for staying current
- FAQ
- Sources
What an NCD is
CMS describes an NCD as its determination of whether a particular item or service is covered, or not covered, nationally under Medicare. It is the broadest coverage instrument in the program. You can read that definition on the CMS page on Medicare coverage of items and services.
The legal footing is in the regulations. Under 42 CFR §405.1060, an NCD is made by the Secretary under section 1862(a)(1) of the Social Security Act and other applicable provisions. The same section makes NCDs binding on:
- fiscal intermediaries and carriers
- Quality Improvement Organizations
- Qualified Independent Contractors
- administrative law judges and attorney adjudicators
- the Medicare Appeals Council
That last part matters when you appeal. If a denial rests on an NCD, you will not win by arguing the NCD is wrong at the appeal level. You win by showing your documentation meets it.
What NCDs typically contain
An NCD states whether Medicare covers an item or service and, in most cases, under what conditions. Those conditions can include the clinical indications, the diagnoses that support medical necessity, and limits on frequency or setting. CMS notes that NCD and LCD policies identify the ICD-10-CM diagnosis codes that support medical necessity, and that providers must use the applicable ICD-10-CM codes for Medicare services.
What an LCD is
CMS defines an LCD as a Medicare contractor's determination of whether a particular item or service is covered on an intermediary-wide or carrier-wide basis under the reasonable-and-necessary standard in section 1862(a)(1)(A). The definition appears on the CMS Local Coverage Determinations page.
Who writes them? CMS explains that fiscal intermediaries, carriers and MACs develop or adopt LCDs. Today that means your MAC, which is the same contractor that processes your Medicare Part B claims.
The CMS Medicare Coverage Database guide states that MACs develop LCDs when no NCD exists or when they need to further define an NCD. That is why you will see LCDs on everything from lesion removal and nerve conduction studies to lab testing and imaging.
LCDs and their articles
The LCD itself is only part of the picture. MACs also publish related articles. According to the CMS document type descriptions, articles often contain coding or other guidance and may support an LCD, while the LCD holds the reasonable-and-necessary coverage language. The same document says LCDs outline how the contractor will review claims to confirm services meet Medicare coverage requirements.
In practice, you read both. The LCD tells you when the service is reasonable and necessary. The article tells you which CPT or HCPCS and ICD-10-CM codes go with it.
LCD vs NCD side by side
| Feature | NCD | LCD |
|---|---|---|
| Issued by | CMS | Your MAC |
| Scope | Nationwide | Within the contractor's jurisdiction |
| When it exists | When CMS decides to set a national rule | When no NCD exists, or to further define one |
| Binding on | Listed contractors and adjudicators, including ALJs and the Appeals Council | Your MAC's claim review within its jurisdiction |
| Can it conflict with the other? | It sets the national floor | Only if it does not conflict with national policy |
| Document ID in the MCD | NCD number | "L" prefix, or "DL" for proposed LCDs |
| Companion documents | Related national guidance | MAC articles with code lists and billing guidance |
The scope difference is the core of it: NCDs apply nationally, while LCDs apply on a contractor-wide basis. A practice in one state can face a different LCD than a practice in another state for the same procedure, because the two practices are served by different MACs.
Which one controls?
The short answer is that the NCD controls. CMS states that an LCD may supplement an NCD only if its policy does not conflict with national policy, as set out on the CMS coverage overview.
The longer answer is more practical. Billers on professional forums often put it this way: the NCD wins on authority, but you still have to meet the LCD to get through your MAC's edits. Both can be true. If an NCD says a service is covered for a given indication and the LCD adds a documentation or frequency requirement that fits within that indication, you need to meet both.
Here is how that looks in three common situations.
- Only an NCD exists. Follow the NCD. Your MAC applies it as written.
- Only an LCD exists. Follow the LCD for your jurisdiction. If you are in a different MAC jurisdiction, that LCD may not apply to you at all.
- Both exist. Start with the NCD, then read the LCD for added detail such as diagnosis lists, frequency limits or documentation expectations. If the LCD seems to contradict the NCD, the NCD governs and you may raise the issue with your MAC.
Why LCD differences cost money
Two practices can bill the same CPT code, with the same clinical picture, and see different results because their MACs wrote different LCDs. A diagnosis that supports medical necessity under one LCD may not appear on another contractor's list. If your practice sees patients across a border, or you open a second location in a different MAC region, check the policies again. Do not assume your first location's rules carry over.
How to look up an LCD or NCD by CPT code
This is the part many billers find confusing. Searchers regularly ask how to find a policy when they only know the CPT code and not the LCD number. The tool for this is the Medicare Coverage Database. CMS describes the MCD as a searchable repository of national and local Original Medicare coverage documents, in its How to Use the MCD guide.
The MCD search page explains why codes matter: if the CPT or HCPCS and ICD-10-CM codes do not align, payment may be rejected. Articles written by MACs carry those code lists.
Here is a repeatable routine:
- Start from the code. Enter the CPT or HCPCS code you plan to bill in the MCD search.
- Choose your state or MAC jurisdiction. An LCD from another contractor does not govern your claims.
- Open the LCD and its article. Read the coverage language in the LCD, then the code lists and billing guidance in the article.
- Check for an NCD. Search the NCD list for the same service. If one exists, read it first.
- Confirm status and dates. In the MCD, check the policy's contractor, state, status, effective dates and related documents.
- Note the ID prefix. LCD IDs begin with "L". Proposed LCDs begin with "DL", which means they are not final.
- Save the policy ID in your billing rules. A policy number in your claim-edit notes beats a bookmark someone will lose.
Watch for proposed and retired policies
A "DL" document is a proposal. It signals what your MAC may adopt, but it is not yet the rule. Under CMS's Program Integrity Manual, chapter 13, the standard LCD process includes public comment and notice of the new policy ahead of its effective date, with some exceptions such as non-substantive corrections. Treat a proposal as an early warning, and set a reminder to review your templates before the final version takes effect.
What to verify before you submit a Medicare claim
CMS's guidance gives you a plain two-part test. Verify that the service is within a Medicare benefit category and is reasonable and necessary, and use the MCD to find coverage information and related coding guidance. That comes from the MCD how-to guide.
Turn that into a pre-bill checklist for any service that has an NCD or LCD:
- Code pairing. Does the CPT or HCPCS code match a diagnosis on the policy's supported list?
- Diagnosis specificity. Is the ICD-10-CM code as specific as the documentation allows? Our guide to ICD-10 specificity in a physician practice covers the common gaps.
- Clinical indication. Does the note state the reason the service was needed, in terms that match the policy?
- Frequency and setting. Does the policy limit how often or where the service can be performed?
- Signature and dates. Is the note authenticated and tied to the date of service?
If the note does not show why the service was necessary, the best code pairing will not save the claim. For concrete note language, see our medical necessity documentation examples. For the denial side of the same problem, read how to stop Medicare medical necessity denials.
A worked example
Say a practice orders a diagnostic service that has an LCD in its jurisdiction. The numbers below are made up to show the process, not real policy.
- The biller searches the CPT code in the MCD and finds an LCD and a linked article for the practice's MAC.
- The article lists a set of ICD-10-CM codes that support medical necessity. The practice's most-used diagnosis code for these patients is unspecified, and is not on the list.
- The physician's note actually describes a specific condition that is on the list, but the coder picked the unspecified code.
- The claim would fail the MAC's edit. After the coder reviews the note and uses the specific code the documentation supports, the claim matches the policy.
The fix was not a coverage argument. It was a documentation and coding match. That is why most LCD and NCD denials are preventable before the claim leaves the building. The coder must never choose a code just because it is on the list. The note has to support the diagnosis.
Where LCD and NCD problems hide in a practice
Policy problems rarely show up as one big error. They show up as patterns:
- Templates that default to unspecified diagnoses, so the code never matches the policy list.
- Orders that omit the clinical reason, leaving the note thin on medical necessity.
- Stale policy knowledge. A staff member learned the rule two years ago and the LCD has since been revised.
- Multi-location drift. A second office in another MAC region follows the first office's rules.
- Edit collisions. A service passes the coverage policy but fails a code-pair edit. Our post on NCCI edits and batch denials shows how to spot those.
It also helps to follow CMS's annual and quarterly update cycle. Our summary of CMS coding updates and action steps gives you a way to schedule policy reviews around those changes.
Our perspective
We work with independent physician practices, and the pattern we see is consistent: the policy text is rarely the problem. The gap is between the policy and what ends up in the chart and on the claim.
Most small practices cannot afford a person whose full-time job is reading MAC policy updates. So the policy sits in a bookmark, a binder or one biller's memory. When that biller is out, or when the MAC revises an LCD, the practice finds out through denials.
We built HIMShield to close that gap. It scans EHR data for coding, documentation and charge-capture gaps before claims go out, scores documentation quality as notes are written, and quantifies what is at risk by provider and payer. When a gap shows up, it drafts the correction for the physician to e-sign in one click, so the fix does not become one more task on a busy day. We also assemble submission-ready responses when a payer audit arrives.
Our advice, whether you use our platform or not: pick the ten highest-volume services in your practice, find the NCD or LCD for each, and compare the policy to ten recent charts. What you find in that exercise will tell you more than any general training session.
— Elena
Find out what policy gaps are costing you
If you would like to see how many claims in your practice miss coverage criteria, our free 30-day audit reviews your EHR data and returns a per-provider, per-payer Revenue Leakage Report. The audit comes with a performance guarantee, and it does not require new staff or software training. Start your free 30-day Revenue Leakage Audit, or learn more about our HIM compliance engagement.
What to do when your practice disagrees with an LCD
You are not stuck with an LCD you think is wrong. CMS says LCD requests may be submitted by beneficiaries, health professionals or other interested parties doing business in the relevant MAC jurisdiction, with evidence and a clear justification of medical use, per the CMS LCD process and timeline page. The Program Integrity Manual adds that a formal request should be in writing, identify the Medicare benefit category and rationale, and state the language you want in the LCD.
For a single denied claim, the route is an appeal, not a policy change. Build the appeal around the policy's own criteria and your documentation. Our one-page appeal letter structure shows how to organize it. If the denial was based on an NCD, remember that adjudicators are bound by it, so your argument has to show the criteria were met.
A short routine for staying current
You do not need a large team. You need a rhythm.
- Monthly: check the MCD for new, revised or proposed LCDs tied to your top services.
- Quarterly: compare denial reports by policy and code to see which LCDs are costing you.
- At every new service line or location: look up the NCD and the LCD for that MAC before the first claim.
- At every template change: confirm the template still captures the clinical indication the policy asks for.
- For services with high audit exposure: keep the policy ID, effective date and a sample compliant note in a shared folder.
Billing for visits is subject to the same logic. A note that fails to show the work behind a level of service invites a downcode or a denial, as in our 99214 documentation checklist. Programs such as care management have their own record requirements too, covered in our chronic care management documentation guide.
FAQ
What does LCD mean in medical billing?
LCD stands for Local Coverage Determination. It is a decision by a Medicare Administrative Contractor on whether a service is reasonable and necessary, and therefore covered, within its jurisdiction. In billing, it tells you which diagnoses, documentation and frequency limits your MAC expects for a given service.
What is an NCD in Medicare?
An NCD, or National Coverage Determination, is CMS's decision on whether Medicare covers a particular item or service nationwide. It binds the listed contractors and adjudicators, including administrative law judges and the Medicare Appeals Council. When an NCD exists, local policy may add detail but may not conflict with it.
Does an NCD override an LCD?
Yes, in the sense that an LCD can supplement an NCD only if it does not conflict with national policy. In day-to-day billing, you should still meet the LCD requirements, because your MAC applies them when it reviews your claims. Start with the NCD, then read the LCD for added local detail.
How do I check whether an LCD or NCD applies to my claim?
Search the Medicare Coverage Database by CPT or HCPCS code, then filter to your state or MAC jurisdiction. Open the LCD and its related article, and confirm the status, effective dates and contractor. Also search the NCD list for the same service, since a national policy may apply even when no LCD does.
Sources
- Medicare Coverage of Items and Services | CMS
- eCFR: 42 CFR Part 405 Subpart I
- Clarifications about NCDs and LCDs | CMS
- Local Coverage Determinations | CMS
- Information about LCDs and LCD Challenges | CMS
- How to Use the Medicare Coverage Database | CMS
- Medicare Coverage Document Type Descriptions | CMS
- MCD Search | CMS
- Medicare Program Integrity Manual, Chapter 13 | CMS
- Local Coverage Determination Process and Timeline | CMS