CARC 304 Active

OA-304: Medical Plan Claim — Submit to Hearing Plan

TL;DR

COB processing identified the hearing plan as the responsible payer. Resubmit to the correct plan.

Action
Verify & Resubmit
Who Pays
Depends
Appeal
Yes
Patient Impact
Indirect
Disclaimer
This content is for informational purposes only and does not constitute professional billing advice. Always verify information against your payer contracts and current coding guidelines. Consult a certified billing specialist for specific claim issues.

What Does OA-304 Mean?

The OA group code indicates the hearing plan redirection was identified during coordination of benefits processing. The secondary payer or COB review determined the hearing plan is responsible.

CARC 304 appears when the medical plan determines the billed service falls under hearing coverage rather than the medical benefit. Insurers that use hearing benefit carve-outs separate hearing services from the medical plan. When the medical plan identifies a claim as hearing-related — such as audiometry, hearing aid fitting, or cochlear implant services — it denies coverage and directs the provider to submit to the hearing plan.

This code functions similarly to CARC 301 (behavioral health redirection) but applies specifically to hearing services. It can also appear when procedure or diagnosis codes on the claim cause the medical plan's classification logic to categorize the service as hearing-related, even if the provider views the service as primarily medical.

Common Causes

Cause Frequency
Hearing benefit identified during COB processing Coordination of benefits processing determined the hearing plan, not the medical plan, is responsible Most Common
Hearing carve-out identified COB review revealed the patient has a separate hearing benefit plan Common

How to Resolve

  1. Review COB information to identify the correct hearing plan
  2. Resubmit the claim to the hearing plan with COB documentation
  3. If the service is medical, appeal with clinical documentation and COB records
Appeal Guide

Appeal with clinical documentation and COB records showing the service should be covered under the medical plan.

Common RARC Pairings

The RARC code tells you exactly what triggered the OA-304:

RARC Description
N527 Payment has been issued to another plan/entity for this claim. Resubmit to the hearing plan identified during COB processing →

How to Prevent OA-304

Also Filed As

The same CARC 304 may appear with different Group Codes:

CO-304 PR-304

Related Denial Codes

OA-301 — Medical Plan Claim — Submit to Behavioral Health Plan OA-305 — Medical Plan Claim — Forwarded to Hearing Plan OA-B11 — Claim Transferred to Proper Payer — Not Covered Here OA-19 — Workers' Compensation Claim OA-20 — Liability Carrier Responsible

Sources

  1. https://x12.org/codes/claim-adjustment-reason-codes
  2. https://www.mdclarity.com/denial-code/304
  3. https://www.cms.gov/medicare/payment/prospective-payment-systems
  4. Codes maintained by X12. Visit x12.org for official definitions.