CO18 Duplicate claim

What better way to get going in 2007 than to analyze why our claims are getting denied by Medicare? The No. 1 denial reason in 2006 was the annoying CO18 (duplicate claim) denial.

One reason for a CO18 denial is that the claim was paid but was rebilled to Medicare before the payment was received or posted. However, this is the best-case scenario and usually is not the main reason for the denial. Another reason is caused by billing for the same HCPC and date of service for different brands. This often happens with wound care, for example, because vendors could make similar items that use the same HCPC. Providers often make the mistake of billing them separately — one line item with three units from the first manufacturer and another line item with five units from the second — instead of combining them.

However, the main cause for the CO18 is that the claim was billed and denied, then resubmitted with the biller’s paying attention to the correction that needed to be made based on the initial denial.

When you receive a CO18 denial, research the claim for previous submissions and find the original denial. Then you must fix the claim and resubmit with the corrected information or appeal the original decision with additional information from the patient chart. If you can’t find the original denial on the EOB or ERA, contact Medicare by calling the Voice Response Unit or using Claim Status Inquiry.

Never simply resubmit a CO18 because it will just get denied again with another CO18, and you will be stuck in a vicious cycle.
— Sarah Hanna

Based on analysis of claims adjudicated by the Medicare contractors between July 1, 2006, and Sept. 30, 2006, and processed for RemitDATA customers. Source: RemitDATA, 866/885-2974, www.remitdata.com.

Sarah Hanna is a reimbursement consultant and vice president of ECS Billing & Consulting, Tiffin, Ohio, and specializes in proper billing protocols, Medicare coverage guidelines and billing office procedures. She can be contacted at 419/448-5332 or [email protected].