The remittance shows a $1,640 infusion denied with CARC CO-50, "not deemed a medical necessity by the payer", and RARC N115, "this decision was based on a Local Coverage Determination". The biller reads it, sighs, and puts it in the appeal pile. Three weeks later a letter goes out that says, in effect, "the doctor felt it was necessary, please reconsider". The payer upholds the denial. The claim is now sixty days older and the practice has spent an hour to lose the same argument twice.
Medical necessity appeals are won on structure, not on feeling. The reviewer on the other end has a coverage policy, a stack of files and a few minutes per case. An appeal that puts the policy criteria and the chart evidence side by side gets read. One that narrates the visit does not. Here is the method we use, the deadlines, and a worked example. This is operational guidance; clinical judgment belongs to the provider, and contract and legal questions belong to counsel.
Key takeaways
- Before writing, answer three questions: does the note meet the payer's stated criteria, is the amount worth the time, and is the deadline still open. Two of the three are checked in five minutes.
- Quote the coverage policy criteria and answer each one with a page and date reference into the attached record. The narrative comes last and stays short.
- Deadlines run from the remittance or denial date: 120 days for a Medicare redetermination, 65 days for a Medicare Advantage reconsideration in 2025, and whatever the contract says for commercial plans.
- Log every appeal and its outcome. A payer that upholds every denial on one service is telling you something about your documentation or its policy, and the fix is upstream either way.
First, decide whether to appeal at all
Before writing, answer three questions. Does the documentation actually support the service against the payer's stated criteria? Is the dollar amount worth the time? Is the deadline still open? A denial where the note is thin should go back to the provider as feedback, not to the payer as an appeal. A $38 denial is usually not worth a letter unless it is one of two hundred identical ones, in which case it is a policy conversation with the payer, not an appeal.
| Payer type | First-level appeal deadline | Levels |
|---|---|---|
| Medicare Part B (fee-for-service) | 120 days from the date of the initial determination (the remittance) for a redetermination | Redetermination by the MAC, reconsideration by a qualified independent contractor (180 days), administrative law judge hearing (60 days, with a minimum amount in controversy), Medicare Appeals Council, federal court |
| Medicare Advantage | 65 days from the denial notice for a standard reconsideration, up from 60 days for notices dated on or after January 1, 2025; check the plan's notice | Plan reconsideration, then automatic forwarding to the independent review entity if the plan upholds |
| Commercial, employer plan under ERISA | At least 180 days for the member appeal; provider appeal windows vary by contract, often 60 to 180 days | Internal appeal (one or two levels), then external review |
| Medicaid managed care | Typically 60 days; varies by state and plan | Plan appeal, then state fair hearing |
The deadline is counted from the date on the remittance or denial letter, not from the day someone noticed it. Record the deadline in the appeal log the day the denial posts. For provider appeals with commercial plans, the contract's provider manual governs, and it often sets a shorter window than the member's rights under the plan document; when the provider window has closed and the member window has not, a member-initiated appeal with the practice's help is sometimes the only path left.
The structure of the letter
- Header block. Patient name and member ID, claim number, date of service, CPT or HCPCS codes and units, billed amount, the denial reason codes exactly as they appear, and the words "Request for redetermination" or "Level 1 appeal" as the payer calls it.
- One-sentence request. "We request reversal of the denial of CPT 96413 on January 14, 2025, because the documentation meets the criteria in [policy name and number]."
- The policy criteria, quoted. Find the LCD, NCD or the payer's medical policy the denial cites. Quote the specific criteria, with the policy number and effective date. If the denial did not name one, ask the payer which policy applied before you write.
- The evidence, criterion by criterion. For each criterion, one or two sentences pointing to the page and date in the attached record where it is met. "Criterion 2, failure of first-line therapy: see progress note of November 4, 2024, page 2, documenting intolerance to methotrexate."
- The clinical summary. Three to five sentences from the treating provider, in plain language, on why this service for this patient. This is the only narrative section and it comes after the criteria, not before.
- The attachments list. Numbered. Only what the reviewer needs: the relevant notes, the order, test results referenced, the prior authorization approval if one exists, the policy excerpt.
- Signature of the treating provider, with NPI, plus the practice contact for questions.
Two pages of letter and a well-labeled packet beat eight pages of chart printout every time. Number the pages of the packet by hand if the system will not, because "see page 4" only works when there is a page 4.
A worked example
A fictional 62-year-old patient with rheumatoid arthritis receives an infusion of a biologic, billed as 96413 with the drug J-code, on January 14, 2025. A Medicare Advantage plan denies both lines with CO-50 and cites its medical policy for the drug. The denial notice is dated February 10, 2025, so the reconsideration request is due by April 16, 2025, and the log says so. The policy requires: a documented diagnosis of moderate to severe RA, inadequate response or intolerance to at least one conventional DMARD, and no active serious infection.
The appeal letter quotes those three criteria and answers each: diagnosis M06.09 documented on the rheumatology consult of August 2024 with a disease activity score; methotrexate trial from August to October 2024 with documented intolerance in the November 4 note; infection screening results dated December 2024 attached. The clinical summary is four sentences. The packet is six pages, numbered. The provider signs. Total staff time, about 45 minutes, against $1,640 on this claim and the same infusion scheduled every eight weeks for the rest of the year. Whether the plan reverses depends on the plan and the record; in our experience an appeal built this way is reviewed on the merits, which a narrative letter often is not.
Now the counter-example. Same patient, but the November 4 note says only "continue current plan" and the methotrexate intolerance lives in the provider's memory. Criterion 2 cannot be pointed to. The right move is not an appeal; it is a conversation with the provider about a late-entry addendum (dated as of when it is written, never backdated) and a documentation habit for future infusions, and a write-off of this claim with a reason code that names documentation, so the loss is visible.
Mistakes that lose appeals with good documentation
The one we see most is sending the entire chart. The reviewer has to find the evidence, and often will not. Close behind it: arguing that the payer's policy is wrong, which is a separate process (a reconsideration request for an LCD, a policy complaint to the plan) and not an appeal; missing the deadline by a day because the denial sat in a work queue; appealing under the wrong process, for example filing a claim reconsideration when the plan requires a formal appeal form; and using the corrected-claim path when nothing on the claim was wrong, which usually produces the same denial a month later. Finally, skipping the peer-to-peer when the plan offers one before the written appeal. A ten-minute physician call sometimes ends the matter, and when it does not, the reviewer's stated objection tells you what the letter must answer.
Track the outcome and feed it back
Every appeal goes in a log: payer, denial reason, service, date sent, level, outcome, date of outcome, dollars recovered. After a quarter, sort by payer and reason. A payer that upholds every necessity denial on a particular service is telling you something about its policy or about your documentation, and either way the fix is upstream. That feedback loop is the difference between denial follow-up and denial management. The numbers worth watching: appeal overturn rate by payer (in our experience a well-run desk sees well over half of first-level necessity appeals overturned when the note supports the service), median days from denial to appeal sent (under 14 is achievable), and the share of necessity denials that were not appealed because the documentation did not support them, which is the number to hand to the providers.
Questions we hear
Who should sign the appeal?
The treating provider, in almost every case. Some payers accept a billing office signature for administrative appeals, but for medical necessity the provider's signature and the provider's summary carry the weight. A signature stamp is not a signature for this purpose.
Can we appeal a denial from months ago?
Only within the payer's window. For Medicare fee-for-service, 120 days from the remittance; a late request can be accepted only with a documented good cause, and "we did not see it" is not one. If the window is closed, most payers will not reopen for necessity, and the claim should be written off with a reason code that says so, so the loss is visible in your denial reporting.
What does Revelrex do differently?
Our denial management team writes appeals to this structure, logs every outcome and reports the pattern back to the practice each month. When the pattern points at documentation, the fix goes to the provider as a specific example, which is the only kind of feedback that changes a note.
What to do this month
- Pull every open CO-50 denial and record its appeal deadline in the log, using the remittance or notice date.
- Sort them into three piles: documentation supports the service, documentation does not, and unclear pending the policy text.
- For the first pile, find the policy cited, quote its criteria, and build the letter to the seven-part structure above.
- For the second pile, write off with a documentation reason code and send one example per provider with the criterion the note failed.
- Update the appeal log template so it captures level, outcome and dollars recovered.
- Ask each Medicare Advantage plan you bill whether it offers a peer-to-peer before the written reconsideration, and note the phone number.
