AGAR Guide
CARC50ReferenceCurrentVerified Aug 15, 2026

CARC 50

AR Guide workflow

Step-by-step: Medical Necessity

✓ Workflow verified Aug 15, 2026 · Verified via review of official sources and AR Guide practice testing — not payer policy. View the full guide

  1. VerifySteps 1–11

    1. The payer's cited policy or guideline

    2. Clinical documentation for the date of service

    3. Service-to-criteria match, point by point

    4. Prior authorization status

    5. Frequency / level of service billed

    6. CARC 50 / 150 / 151 and the accompanying remark code

    7. Review the payer's medical policy or coverage determination cited in the denial

    8. Confirm the clinical documentation supports the service

    9. Check whether a prior authorization would have prevented the denial

    10. Ask the payer to cite the specific policy or guideline used

    11. Compare the service to the policy's criteria point by point

  2. ActSteps 12–15

    1. Appeal with clinical documentation that addresses the cited criteria

    2. Reference the applicable policy in the appeal

    3. If the payer cannot cite a policy, escalate — denials must be based on a defined policy

    4. For experimental denials, gather peer-reviewed evidence supporting the service

  3. Document & QASteps 16–22

    1. Clinical notes and records for the date of service

    2. The payer's cited policy and the criteria met

    3. Peer-reviewed literature for experimental/investigational appeals

    4. Any prior authorization or approval documentation

    5. Attach supporting clinical documentation on the first appeal

    6. Track denial reasons by payer and policy to spot patterns

    7. Verify the payer cites a specific policy before appealing

Appeal with documentation that meets the cited criteria: Heads up

Medical-necessity denials are documentation-driven: the payer applied a specific policy, and the appeal wins by addressing its criteria point by point — not by resubmitting the same claim.

If you take the wrong path: A bare resubmission is denied again. A first appeal without the supporting clinical documentation wastes the strongest appeal you have.

AR Guide explanation

What it means

The payer determined the services were not medically necessary according to its policy.

AR Guide knowledge

Common denial category

Medical Necessity — The payer determined the service was not medically necessary or reasonable according to its policy. These denials are documentation-driven.

AR Guide knowledge

Most common causes

  • Documentation does not support the level of care
  • Service not covered by the payer's medical policy
  • Missing clinical documentation at the time of review

AR Guide knowledge

Action in your PM/EMR system

In your PM system: route the claim to your appeals queue with the clinical documentation attached. Do not resubmit the same claim — pull the payer's cited policy and map your documentation to its criteria.

Illustrative scenario

Real-world example

A level-4 visit was denied with CARC 50 because the documentation did not support the level. The appeal attached the full note mapped to the payer's criteria and the level was upheld on reconsideration.

Example — not a claim about any specific payer or account.

AR Guide knowledge

What AR should verify

  1. Review the payer's medical policy or coverage determination cited for the denial
  2. Confirm the clinical documentation supports the service
  3. Check whether a prior authorization would have prevented the denial

AR Guide knowledge

Recommended action

  1. Appeal with clinical documentation and a reference to the applicable policy
  2. Ask the payer to cite the specific policy or guideline used

Appeal template

Medical Necessity Appeal — Criterion-by-Criterion Response

Respond to a medical-necessity denial by addressing each policy criterion with the documentation that meets it.

For: Clinical + billing staff appealing CARC 50 / 151 denials with supporting documentation. · Last reviewed 2026-08-16

Download .doc template

Educational starting point — not legal advice. Customize every [bracketed] placeholder and verify the payer's appeal address and deadline from the payer's own documentation. All templates

AR Guide knowledge

Escalation

  • If the payer cannot cite a specific policy, escalate — denials must be based on a defined policy.

AR Guide knowledge

QA checkpoint

  • Attach supporting clinical documentation on the first appeal
  • Track denial reasons by payer and policy to spot patterns

About this guidance: Note

AR Guide knowledge is general reference content written by our team — it is not payer-specific policy and never replaces the payer’s documentation or your contract. Always confirm specifics with the payer.

Priority 2

Commonly paired RARCs

RARCs commonly accompany CARC 50 on the ERA/EOB. Select the one on your line to focus the workflow, or use the list as a lookup.

  • RARCN386This decision was based on a National Coverage Determination (NCD). An NCD provides a coverage determination as to whether a particular item or service is covered. Visit CMS.gov and search for Medicare Coverage Database to find a copy of the policy.Review the cited NCD. If the service meets the NCD conditions, appeal with documentation showing each condition is satisfied.
  • RARCN29Missing documentation/orders/notes/summary/report/chart.Send the requested documentation through the payer's preferred channel and reference the claim number. Track the submission so it can be proven later.
  • RARCM25The information furnished does not substantiate the need for this level of service. If you believe the service should have been fully covered as billed, or if you did not know and could not reasonably have been expected to know that we would not pay for this level of service, or if you notified the patient in writing in advance that we would not pay for this level of service and he/she agreed in writing to pay, ask us to review your claim within 120 days of the date of this notice. If you do not request an appeal, we will, upon application from the patient, reimburse him/her for the amount you have collected from him/her in excess of any deductible and coinsurance amounts. We will recover the reimbursement from you as an overpayment.Map the note to the billed level's documentation requirements (history, exam, medical decision making). If the note supports the level, appeal with the documentation mapped to the criteria; if not, correct the level and resubmit.

Priority 3

Payer-specific nuance

How major payers handle this denial — what AR Guide has verified, and what you must confirm with the payer. We never publish payer handling we have not verified.

Medicare

Medical necessity is judged against each payer's specific policy and clinical criteria. Ask the payer to cite the policy used, then verify your documentation addresses its criteria point by point in the appeal.

Medicaid

Medical necessity is judged against each payer's specific policy and clinical criteria. Ask the payer to cite the policy used, then verify your documentation addresses its criteria point by point in the appeal.

UnitedHealthcare

Medical necessity is judged against each payer's specific policy and clinical criteria. Ask the payer to cite the policy used, then verify your documentation addresses its criteria point by point in the appeal.

Aetna

Medical necessity is judged against each payer's specific policy and clinical criteria. Ask the payer to cite the policy used, then verify your documentation addresses its criteria point by point in the appeal.

Cigna

Medical necessity is judged against each payer's specific policy and clinical criteria. Ask the payer to cite the policy used, then verify your documentation addresses its criteria point by point in the appeal.

Anthem (BCBS)

Medical necessity is judged against each payer's specific policy and clinical criteria. Ask the payer to cite the policy used, then verify your documentation addresses its criteria point by point in the appeal.

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