AGAR Guide
CARC15ReferenceHistorical / DeactivatedVerified Aug 15, 2026

CARC 15

Historical / Deactivated code: Heads up

CARC 15 is no longer valid for current transactions. It may still appear on older remittance advices — treat it as reference for historical documents only.

AR Guide workflow

Step-by-step: Authorization

✓ 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. Authorization number on file

    2. Authorization dates of service

    3. Service and provider match the authorization

    4. Whether authorization was actually required (benefit design)

    5. Whether retro-authorization is possible

    6. CARC 197 / 15 / 210 and the accompanying remark code

    7. Pull the authorization record and compare number, dates, services, and provider

    8. Confirm the authorization covered the date of service

    9. Check whether the payer offers retro-authorization for already-rendered services

    10. Verify the authorization was submitted on the claim correctly

    11. Confirm the authorization requirement for the specific service

  2. ActSteps 12–15

    1. If a valid authorization exists, appeal with the authorization reference

    2. If the service is already rendered, request a retro-authorization or appeal with clinical necessity

    3. If not yet rendered, obtain authorization before the service

    4. Attach the authorization number at claim entry for future claims

  3. Document & QASteps 16–22

    1. Authorization reference number and approval details

    2. Authorization request and response timestamps

    3. Clinical justification for the service

    4. Payer correspondence showing the requirement

    5. Verify authorization requirements at scheduling, not after the denial

    6. Track authorization expiration dates and service limits

    7. Attach the authorization number to the claim at entry

Retro-authorize, appeal with the auth — or get it before service: Note

If a valid authorization exists, appeal with the reference. If the service is already rendered, pursue a retro-authorization or an appeal with clinical necessity. If it is not yet rendered, obtain the authorization first.

If you take the wrong path: Appealing without the authorization record fails. Rendering a service that requires authorization without one creates a likely uncollectable write-off.

AR Guide explanation

What it means

The authorization number was missing, invalid, or did not apply to the billed services or provider. Note: this code was deactivated by ASC X12.

AR Guide knowledge

Common denial category

Authorization — The service required prior authorization, precertification, or pre-treatment review that was missing, expired, or did not cover what was billed.

AR Guide knowledge

Most common causes

  • Authorization not obtained before service
  • Wrong authorization number on the claim
  • Authorization does not cover the service/provider billed

AR Guide knowledge

Action in your PM/EMR system

In your PM system: check the authorization record for the date of service and provider. If a valid auth exists, attach the reference and appeal. If not, request a retro-authorization through the payer's portal before deciding to appeal.

Illustrative scenario

Real-world example

A procedure was denied with CARC 197 because the authorization number on the claim did not match the service date. The provider attached the valid authorization and appealed successfully.

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

AR Guide knowledge

What AR should verify

  1. Pull the authorization record and compare the number, dates, services and provider
  2. Check authorization dates of service coverage

AR Guide knowledge

Recommended action

  1. Correct and resubmit with the valid authorization number, or
  2. Request a retro-authorization if the service is already rendered

Appeal template

Authorization Appeal — Valid Authorization on File

Appeal a missing/expired authorization denial where an authorization existed but was misapplied or expired in processing.

For: Billing staff appealing CARC 197 / 15 denials with the original authorization number. · 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

QA checkpoint

  • Attach the authorization number at claim entry
  • Track authorization expiration dates

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 15 on the ERA/EOB. Select the one on your line to focus the workflow, or use the list as a lookup.

  • RARCN41Authorization request denied.
  • RARCN54Claim information is inconsistent with pre-certified/authorized services.
  • RARCN27Missing/incomplete/invalid treatment number.
  • RARCM62Missing/incomplete/invalid treatment authorization code.
  • 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.

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

Authorization requirements, valid channels, and retro-authorization options are payer- and plan-specific. Confirm the requirement for the exact service, date and provider with the payer before appealing.

Medicaid

Authorization requirements, valid channels, and retro-authorization options are payer- and plan-specific. Confirm the requirement for the exact service, date and provider with the payer before appealing.

UnitedHealthcare

Authorization requirements, valid channels, and retro-authorization options are payer- and plan-specific. Confirm the requirement for the exact service, date and provider with the payer before appealing.

Aetna

Authorization requirements, valid channels, and retro-authorization options are payer- and plan-specific. Confirm the requirement for the exact service, date and provider with the payer before appealing.

Cigna

Authorization requirements, valid channels, and retro-authorization options are payer- and plan-specific. Confirm the requirement for the exact service, date and provider with the payer before appealing.

Anthem (BCBS)

Authorization requirements, valid channels, and retro-authorization options are payer- and plan-specific. Confirm the requirement for the exact service, date and provider with the payer before appealing.

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