CO-304: Benefits Not Available — Submit to Hearing Plan
The medical plan does not cover hearing services. Redirect the claim to the patient's hearing plan. Do not bill the patient until the hearing plan has adjudicated.
What Does CO-304 Mean?
CO-304 is the standard pairing, indicating the medical plan is adjusting the claim as a contractual matter because hearing benefits simply do not exist under this plan. The provider should not write off the charges permanently — instead, redirect the claim to the hearing plan. The CO designation means you cannot bill the patient while the hearing plan claim is pending. Only if the hearing plan also denies or the patient has no hearing plan should patient billing be considered.
When CARC 304 appears on a remittance, the medical plan is informing you that the services billed — typically audiological exams, hearing aid fittings, or hearing-related procedures — are not covered under the patient's general medical insurance. Instead, these services must be submitted to the patient's separate hearing benefit plan for adjudication.
Many commercial insurance carriers carve out hearing benefits into separate specialty plans administered by different entities. When a hearing-related claim is submitted to the medical plan, the medical plan cannot process it because the benefits exist under a different plan with a different payer ID and billing pathway. CARC 304 specifically instructs the provider to submit the claim to the hearing plan rather than simply denying it.
The key distinction between CARC 304 and CARC 305 is important: CARC 304 tells you to submit the claim yourself to the hearing plan, while CARC 305 means the medical plan has already forwarded the claim to the hearing plan on your behalf. When you receive CARC 304, the ball is in your court to identify the correct hearing plan payer and resubmit.
Common Causes
| Cause | Frequency |
|---|---|
| Hearing services billed to medical plan instead of hearing plan The claim for hearing-related services (audiological exams, hearing aids, hearing aid fittings) was submitted to the patient's general medical insurance plan, which does not cover hearing benefits — these must be billed to the separate hearing plan | Most Common |
| Incorrect insurance information on file The patient's hearing plan information was not collected or was entered incorrectly, causing the claim to be routed to the medical plan by default | Most Common |
| Coordination of benefits routing error In a COB scenario, the claim was submitted to the primary medical plan when it should have been directed to the hearing plan, or the hearing plan was not identified as the responsible payer for these services | Common |
| Plan exclusions for hearing services The patient's medical plan explicitly excludes hearing-related services from coverage, requiring them to be billed to a separate hearing benefit plan | Common |
| Non-participating provider for hearing plan The provider is not contracted with the patient's hearing plan network, leading to billing the medical plan instead, which does not cover these services | Occasional |
How to Resolve
Identify the patient's hearing plan and resubmit the claim directly to that payer.
- Obtain the hearing plan details Collect the hearing plan payer ID, member ID, and group number from the patient's insurance card or by contacting the medical plan's customer service line.
- Submit to the hearing plan Prepare and submit the claim to the hearing plan using the correct identifiers. Include all supporting documentation including audiological reports and medical necessity justification.
- Track the hearing plan adjudication Monitor the claim with the hearing plan and follow up if payment is not received within the expected processing window.
This is a standard contractual adjustment. The amount is a provider write-off per your payer contract.
Common RARC Pairings
The RARC code tells you exactly what triggered the CO-304:
| RARC | Description |
|---|---|
| N130 | Alert: You may need to review plan documents or guidelines to determine coverage restrictions or benefits available under the patient's hearing plan. |
| N381 | Alert: Consult your contractual agreement for billing and payment information related to these charges. |
How to Prevent CO-304
- Ask patients about separate hearing plans during registration and collect the hearing plan information before services are rendered
- Maintain a reference list of major medical insurers that carve out hearing benefits to separate plans
- Implement claim routing rules that flag hearing-related CPT codes for submission to the hearing plan rather than the medical plan
General Prevention
- Collect and verify all insurance plan details during patient registration, specifically asking about separate hearing, vision, and dental plans
- Verify hearing plan eligibility and benefits before rendering hearing-related services to confirm the correct payer and billing requirements
- Maintain a reference list of services that are commonly carved out to separate hearing plans by major medical insurers
- Train front-desk and billing staff to identify hearing-related services that may need to be billed to a separate hearing plan
- Implement a claims scrubbing process that flags hearing-related procedure codes for routing to the hearing plan rather than the medical plan
Also Filed As
The same CARC 304 may appear with different Group Codes:
Related Denial Codes
Sources
- https://www.mdclarity.com/denial-code/304
- https://x12.org/codes/claim-adjustment-reason-codes
- Codes maintained by X12. Visit x12.org for official definitions.