EOB denial code CO-109: what it means

What it means

This insurer is not the right payer for this claim — it should go to a different plan or contractor.

Contractual Obligation — an adjustment the provider agreed to by contract. The patient is generally not billed for CO amounts.

Official X12 description

“Claim/service not covered by this payer/contractor”

Typical cause

The claim was sent to the wrong insurer, or another payer (such as Medicare or a different plan) is responsible.

What to do next

1. 1Confirm which insurer or plan should receive this claim.
2. 2Ask your provider's billing office to resubmit to the correct payer.