CO 18 Denial Code: Resolve Duplicate Claim/Service Issues | Allzone

The CO 18 denial code signals that an insurance payer considers a claim a duplicate of one already processed. For healthcare providers, repeated CO 18 denials result in revenue loss, wasted administrative time, and cash flow delays. In this in-depth guide, Allzone Management Services breaks down the causes of duplicate claim denials — such as system errors, incorrect modifiers, or premature resubmissions — and shares proven strategies to prevent them. You’ll learn best practices like front-end verification, claim scrubbing, correct use of frequency codes and modifiers, real-time claim tracking, and root cause analysis. Partnering with Allzone’s denial management expertise means fewer denials, quicker reimbursements, and smoother revenue cycle operations. Read on to see how to fix CO 18 denials and safeguard your practice’s financial health.