CARC 301 Active

CO-301: Medical Plan Claim — Submit to Behavioral Health Plan

TL;DR

CO-301 means the medical plan contractually denies the service. Submit to the patient's behavioral health plan. Do not bill the patient for the CO adjustment.

Action

Verify & Resubmit

Who Pays

Provider

Appeal

Yes

Patient Impact

None

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 CO-301 Mean?

When CARC 301 appears with CO, the medical plan is contractually denying the behavioral health service. The provider cannot bill the patient for the medical plan's denied amount. The provider must submit the claim to the behavioral health plan to receive payment.

CARC 301 indicates the medical plan received the claim, determined the service falls under behavioral health coverage, and is directing the provider to submit the claim to the patient's behavioral health plan. Unlike CARC 300 where the medical plan automatically forwards the claim, CARC 301 places the resubmission responsibility squarely on the provider.

This code appears when behavioral health services such as psychotherapy, psychiatric evaluations, substance abuse treatment, or behavioral assessments are billed to the medical plan but the plan uses a behavioral health carve-out arrangement. The medical plan will not process the claim and will not forward it on the provider's behalf. The provider must identify the correct behavioral health plan, obtain the payer information, and submit the claim directly.

Behavioral health carve-outs are common in commercial insurance and employer-sponsored plans. The behavioral health administrator may be a completely separate entity from the medical plan, with different payer IDs, submission requirements, and claim forms. Providers of behavioral health services should identify these carve-out arrangements during patient intake to avoid submitting to the wrong plan and experiencing the delay caused by a CARC 301 denial.

Common Causes

Cause	Frequency
Service classified as behavioral health Medical plan determined the service falls under behavioral health coverage and the provider must submit to the behavioral health plan manually	Most Common
Behavioral health carve-out Patient's plan uses a behavioral health carve-out and the medical plan does not process behavioral health claims	Most Common
Incorrect plan submission Provider submitted behavioral health services to the medical plan instead of the appropriate behavioral health plan	Common
Missing pre-authorization from behavioral health plan Required preauthorization was not obtained from the behavioral health plan before services were rendered	Common
Billing errors or incorrect coding Incorrect diagnosis or procedure codes led the medical plan to reject the claim as a behavioral health service	Common
Policy changes excluding services Recent coverage updates to the medical plan now exclude certain behavioral health services that were previously covered	Occasional

How to Resolve

Identify the patient's behavioral health plan and submit the claim directly with all required documentation.

Submit to behavioral health plan Get the patient's behavioral health plan details and submit the claim directly. This is the only path to payment.
Appeal if misclassified If you believe the service is medical rather than behavioral health (e.g., neurobehavioral testing for a medical condition), appeal the medical plan denial with supporting clinical documentation.

How to Prevent CO-301

Identify behavioral health carve-outs during patient registration by asking about separate mental health coverage
Bill behavioral health services directly to the behavioral health plan from the outset
Maintain a database of payer-specific behavioral health carve-out relationships

General Prevention

Verify whether the patient has a separate behavioral health plan during registration
Conduct thorough eligibility checks to determine the correct plan for behavioral health services
Establish communication with behavioral health plans before rendering services
Train staff on coverage distinctions between medical and behavioral health plans
Use electronic claim submission systems that route claims to the correct plan

Also Filed As

The same CARC 301 may appear with different Group Codes:

OA-301

Related Denial Codes

CO-19 — Workers' Compensation Claim CO-20 — Liability Carrier Responsible CO-21 — No-Fault Carrier Responsible CO-22 — Care Covered by Another Payer (COB) CO-26 — Expenses Incurred Prior to Coverage

Sources

https://www.mdclarity.com/denial-code/301
https://x12.org/codes/claim-adjustment-reason-codes
Codes maintained by X12. Visit x12.org for official definitions.