CARC 300 Active

CO-300: Medical Plan Claim Forwarded to Behavioral Health Plan

TL;DR

CO-300 means the medical plan contractually denies the service and forwarded it to behavioral health. Wait for the behavioral health plan's determination.

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-300 Mean?

When CARC 300 appears with CO, the medical plan is contractually denying the behavioral health service and forwarding it. The provider cannot bill the patient for the medical plan denial while waiting for the behavioral health plan to adjudicate.

CARC 300 is a claim routing code indicating the medical plan received the claim, determined the service belongs under behavioral health coverage, and has automatically forwarded it to the patient's behavioral health plan for processing. This code is a forwarding confirmation, not a final denial.

This code is common in managed care arrangements where behavioral health benefits are carved out and managed by a separate entity. Many employers and health plans contract with specialty behavioral health organizations like Optum Behavioral Health, Carelon Behavioral Health, or Magellan to administer mental health and substance abuse benefits separately from medical/surgical benefits. When a provider submits a behavioral health claim to the medical plan, the medical plan recognizes the service type and routes it to the carved-out behavioral health administrator.

The distinction between CARC 300 and CARC 301 is important. CARC 300 means the medical plan has forwarded the claim to the behavioral health plan on your behalf. CARC 301 means the medical plan is telling you to submit the claim to the behavioral health plan yourself. With CARC 300, the claim should already be in the behavioral health plan's queue, but active follow-up is still recommended to ensure the forwarding was successful.

Common Causes

Cause Frequency
Behavioral health carve-out Patient's plan has a behavioral health carve-out where mental health and substance abuse services are managed separately from medical/surgical benefits Most Common
Service classified as behavioral health Medical plan determined the service falls under behavioral health coverage based on diagnosis or procedure codes Most Common
Claim submitted to wrong plan Provider submitted behavioral health services to the medical plan instead of the behavioral health plan Common
Coordination of benefits routing Medical plan forwards behavioral health claims to the appropriate behavioral health insurer per COB rules Common
Missing pre-authorization from correct plan Required approvals were not obtained from the behavioral health plan before service delivery Occasional

How to Resolve

Confirm the behavioral health plan received the forwarded claim and monitor it through adjudication.

  1. Track behavioral health plan processing Monitor the behavioral health plan's adjudication. Do not take any write-off action until the behavioral health plan has processed the claim.
  2. Post adjustments after determination Once the behavioral health plan processes the claim, post payment or adjustments accordingly.

How to Prevent CO-300

General Prevention

Also Filed As

The same CARC 300 may appear with different Group Codes:

Related Denial Codes

Sources

  1. https://www.mdclarity.com/denial-code/300
  2. https://x12.org/codes/claim-adjustment-reason-codes
  3. Codes maintained by X12. Visit x12.org for official definitions.