CO-P8: Claim Under Investigation

What Does CO-P8 Mean?

CO-P8 is less common but may appear when the investigation results in a payment hold that the carrier processes as a contractual adjustment during the investigation period. This does not necessarily mean the claim is permanently denied — it may be reprocessed once the investigation concludes.

CARC P8 signals that the Property and Casualty carrier has placed the claim under investigation and is withholding payment until the investigation concludes. This code replaces the older CARC 221 and is exclusive to P&C claims. Unlike a final denial, P8 is a temporary hold — the carrier has not yet made a coverage or payment determination.

Investigations are triggered by a variety of factors. The carrier may have flagged the claim for suspected fraud, identified billing irregularities or unusual patterns, discovered discrepancies in the documentation, or is investigating the underlying liability or coverage status of the P&C claim. In some cases, an external investigation by law enforcement, a regulatory body, or an independent adjuster may be involved.

The provider's role during a P8 investigation is to cooperate fully and provide any documentation the carrier requests promptly. Fighting a P8 hold through a formal appeal is premature since no final determination has been made. The appropriate response is to maintain contact with the carrier's claims department, understand the investigation scope and timeline, and track the claim for follow-up. If the investigation is unreasonably prolonged, the provider can escalate through the carrier's provider relations team or file a complaint with the state insurance regulator.

How to Resolve

Cooperate with the carrier's investigation, provide requested documentation, and track the claim until a final determination is issued.

1. Confirm the adjustment is investigation-related Contact the carrier to confirm that CO-P8 is an interim hold and not a final denial. Ask whether the claim will be automatically reprocessed after the investigation.
2. Cooperate with the investigation Provide all requested documentation and respond to carrier inquiries promptly.
3. Request reprocessing after resolution Once the investigation concludes, contact the carrier to request claim reprocessing if it does not happen automatically.

How to Prevent CO-P8

• Maintain thorough documentation for all P&C claims to minimize investigation triggers
• Implement internal compliance audits to catch billing irregularities before they are flagged by payers

Also Filed As

The same CARC P8 may appear with different Group Codes:

Related Denial Codes