NOMNC vs DENC: The Two Medicare Non-Coverage Notices, Explained
The NOMNC and the DENC are two different Medicare notices with two different jobs. The NOMNC (CMS-10123) tells you coverage is ending; the DENC (CMS-10124) explains why, and you only get it after you appeal. Here is who issues each, when, and what each must contain.
Two notices govern a post-acute discharge appeal, and people constantly confuse them. The Notice of Medicare Non-Coverage (NOMNC, CMS-10123) is the short generic notice the provider must give you at least 2 days before Medicare-covered services end; it tells you the coverage-end date and that you can request an expedited BFCC-QIO review. The Detailed Explanation of Non-Coverage (DENC, CMS-10124) is the longer, case-specific notice that explains exactly why coverage is ending, and, crucially, you only receive it after you file the expedited appeal. In short: the NOMNC starts the clock; the DENC gives you the reasons to argue against. Both are standardized CMS forms used in SNF, home health, hospice, and CORF settings, for both Original Medicare and Medicare Advantage. Your actual notice controls the dates.
In a Medicare post-acute discharge appeal, two documents do all the work, and telling them apart is the difference between a confused family and a prepared one. One is generic and arrives first; the other is specific and arrives only if you push back. Providers deliver the first as a matter of routine and the second only in response to an appeal, so many families never see the second at all, which is a shame, because the second is the one that hands you the argument. This guide lays out the Notice of Medicare Non-Coverage (NOMNC) and the Detailed Explanation of Non-Coverage (DENC) side by side: who issues each, the timing, and what each is required to contain. Apellica helps families and facilities read these notices and organize a response; it is not Medicare, a regulator, a law firm, or a provider, and this is general information, not advice.
The NOMNC: the generic notice that starts the clock
The Notice of Medicare Non-Coverage is CMS form CMS-10123. Under 42 CFR 405.1200, the provider must deliver it to the beneficiary no later than 2 days before the proposed end of covered services. It is a short, standardized form, and its job is narrow: tell you the date Medicare coverage will end and tell you that you have the right to an expedited determination, including how to request one and the BFCC-QIO phone number to call.
What the NOMNC does not do is explain the clinical reasoning. It will not walk through your chart or cite the specific coverage rule the facility applied. That level of detail is reserved for the second notice, and only if you ask for it by appealing.
Because the NOMNC is what starts the appeal clock, it is the document to act on immediately. The deadline to request the BFCC-QIO review, generally noon of the calendar day after you receive the NOMNC, is driven by this notice, not the DENC.
The DENC: the detailed notice you only get if you appeal
The Detailed Explanation of Non-Coverage is CMS form CMS-10124. Per CMS's Beneficiary Notices Initiative, it is given only if a beneficiary requests an expedited determination, and it explains the specific reasons for the end of covered services. In other words, filing the fast appeal is what triggers the DENC.
The DENC is where the case-specific substance lives. Consistent with the expedited-determination rules at 42 CFR 405.1202, the detailed notice is expected to include a specific and detailed explanation of why services are either no longer reasonable and necessary or no longer covered, a description of any applicable Medicare coverage rule or policy, and the facts specific to the beneficiary that are relevant to the coverage decision.
That structure makes the DENC your rebuttal checklist. Each stated reason is a claim you (with your clinician's help) can answer point by point in front of the BFCC-QIO. Without the DENC, you are arguing against reasons you have not been shown; with it, you have the facility's own stated grounds in writing.
NOMNC vs DENC at a glance
| Feature | NOMNC (CMS-10123) | DENC (CMS-10124) |
|---|---|---|
| Purpose | Tells you covered services are ending and that you can appeal | Explains the specific reasons coverage is ending |
| When you get it | At least 2 days before the coverage-end date | Only after you request an expedited determination |
| Who issues it | The provider (SNF, home health agency, hospice, CORF) | The provider (and, in MA cases, with plan input) |
| Level of detail | Generic; date and appeal rights | Case-specific clinical reasoning and coverage rule |
| Its main job for you | Starts the appeal clock | Gives you the reasons to argue against |
| Settings | SNF, home health, hospice, CORF | SNF, home health, hospice, CORF |
Who issues each, and when
The provider delivering your care, the skilled nursing facility, home health agency, hospice, or comprehensive outpatient rehabilitation facility, is responsible for delivering the NOMNC on time. In a Medicare Advantage case the plan is behind the coverage decision, but the provider still delivers the notice.
The DENC follows the appeal. Once you contact the BFCC-QIO and request the expedited determination, the provider (in MA cases, working with the plan) prepares and delivers the DENC so that you and the reviewer have the specific reasons in hand. The BFCC-QIO uses the medical record plus this explanation to decide whether ending coverage on the stated date is correct.
Both notices are standardized national CMS forms, which means the layout is the same whether you are in Original Medicare or Medicare Advantage and whatever facility you are in. The content, dates, and phone numbers, of course, are specific to you, and your actual notice always controls.
Why the distinction matters for your appeal
The two-notice structure has a practical consequence: you must appeal to see the reasons, and you must appeal fast. If you wait for a detailed explanation before deciding whether to fight, you will wait forever, because the detailed explanation only comes after you fight. The correct sequence is to treat the NOMNC as the trigger, call the BFCC-QIO by the deadline, and then use the DENC to build the argument.
It also means the quality of your appeal improves the moment the DENC arrives. Many families make an initial, general appeal on the NOMNC deadline, then sharpen it against the DENC's specifics once it is delivered. Apellica helps organize exactly this: capturing the notices, mapping the DENC's stated reasons to the record, and tracking the short deadlines so nothing lapses.
Frequently asked questions
Do I automatically get a DENC?
No. The DENC (CMS-10124) is issued only after you request an expedited determination from the BFCC-QIO. The NOMNC (CMS-10123) comes first automatically; the DENC comes only in response to your appeal. That is why filing the fast appeal is what unlocks the detailed reasons.
Which notice starts the appeal deadline?
The NOMNC. Under 42 CFR 405.1202 you must request the expedited BFCC-QIO review no later than noon of the calendar day after you receive the NOMNC. The DENC arrives later and does not reset that deadline. Rely on the dates printed on your NOMNC.
What must the DENC contain?
Consistent with 42 CFR 405.1202, the DENC is expected to give a specific and detailed explanation of why services are no longer reasonable and necessary or no longer covered, a description of the applicable Medicare coverage rule or policy, and the facts specific to you that are relevant to the decision. That makes it your point-by-point rebuttal checklist.
Who fills out these notices?
The provider delivering your care, the SNF, home health agency, hospice, or CORF, delivers the NOMNC and prepares the DENC. In a Medicare Advantage case, the plan is behind the coverage decision, but the provider still delivers the notice, and the DENC may be prepared with plan input.
Are the NOMNC and DENC used in Medicare Advantage too?
Yes. Both CMS-10123 and CMS-10124 are national forms used for both Original Medicare (fee-for-service) and Medicare Advantage. The first BFCC-QIO step is the same; the later appeal ladder differs, which the Medicare Advantage SNF discharge guide covers.
The NOMNC was handed to me the same day my coverage ended. Is that a problem?
Possibly. Under 42 CFR 405.1200 the provider must deliver a valid NOMNC no later than 2 days before the coverage-end date. If it was late or not properly explained, that is worth raising, and Medicare guidance provides that coverage of provider services generally continues until at least 2 days after you receive valid notice. Confirm the specifics on your own notice.
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