Why request the medical policy rather than just argue the case?

Because you cannot rebut criteria you have not read, and payers apply the version in force on the date of service — which may not be the one currently published. Requesting it also creates a record that you asked.

Is a clinician's letter enough on its own?

Rarely. A statement of clinical opinion carries far less weight than the same clinician's contemporaneous notes mapped against the payer's criteria. Use the record first and the statement to tie it together.

CO-50

Appeal letter template: not deemed medically necessary (CO-50)

For clinical denials. Structured to argue from the payer's own coverage criteria rather than asserting necessity, which is what distinguishes the appeals that win.

Free, no signup required to read or copy it. Replace every bracketed field before sending, and refer to the patient by initials and account reference only — never a full name.

Use this when

The remittance shows CO-50 or states the service was not medically necessary.
The denial cites a coverage policy or determination you can obtain.
The clinical record documents criteria the payer says were not met.
Documentation existed at the time of service but was not sent with the claim.

The letter

[PRACTICE NAME]
[PRACTICE ADDRESS]
[PHONE] · [FAX]

[DATE]

[PAYER NAME] — Appeals Department
[APPEALS ADDRESS FROM YOUR REMITTANCE]

RE: Appeal of claim denial
Claim number: [CLAIM NUMBER]
Patient reference: [PATIENT INITIALS] / [ACCOUNT REFERENCE]
Date of service: [DATE OF SERVICE]
Billed amount: [AMOUNT]
Denial code: CO-50 — not deemed a medical necessity by the payer

To the Appeals Department:

We are appealing the denial of the claim identified above, which was denied on medical necessity grounds.

The clinical record supports the service as provided, and we believe it meets the coverage criteria applicable on the date of service.

Clinical summary drawn from the record:
[SUMMARIZE FROM THE RECORD — presenting condition, relevant history, prior conservative treatment and its duration and outcome, findings that supported the decision to proceed, and the clinical rationale documented at the time]

Criteria review:
[FOR EACH CRITERION IN THE PAYER'S POLICY, STATE THE CRITERION AND WHERE IN THE RECORD IT IS MET — for example: "Criterion: documented failure of conservative management for at least six weeks. Met: office notes dated [DATES] document [TREATMENT] over [DURATION] without sustained improvement."]

So that we can respond to the specific basis for this determination, we request:
- The medical policy or coverage determination relied upon, and the version in force on the date of service
- The specialty of the clinician who conducted the review
- The opportunity for a peer-to-peer discussion with the reviewing clinician

Attached in support of this appeal:
[LIST ATTACHMENTS — office notes, imaging or test results, prior treatment records, ordering clinician's statement]

We ask that you reprocess this claim and remit payment in the amount of [AMOUNT].

Please provide a written determination within your stated appeal-response window. If any additional documentation would assist the review, contact me directly at [PHONE] or [EMAIL].

Sincerely,

[NAME]
[TITLE]
[PRACTICE NAME]
[NPI / TAX ID]

How to adapt it

The criteria review is the part that wins. Pull the payer's actual policy and answer it criterion by criterion — an appeal that asserts necessity without mapping to criteria is usually upheld.
Request the reviewing clinician's specialty. A review conducted outside the relevant specialty is itself worth raising.
Ask for the peer-to-peer early: that window is often much shorter than the written appeal window, and the two run in parallel.

Understand the denial first

CO-50CO-50 denial: not deemed medically necessaryThe payer decided the service was not medically necessary under its coverage policy for this diagnosis and setting.

Common questions

Why request the medical policy rather than just argue the case?: Because you cannot rebut criteria you have not read, and payers apply the version in force on the date of service — which may not be the one currently published. Requesting it also creates a record that you asked.
Is a clinician's letter enough on its own?: Rarely. A statement of clinical opinion carries far less weight than the same clinician's contemporaneous notes mapped against the payer's criteria. Use the record first and the statement to tie it together.

Or skip the blanks entirely

Undeny reads the denial document, fills every one of these fields from it, and tracks the appeal deadline. About three minutes instead of thirty.

Generate your appeal letter See pricing