Denial code CO-109

What does Denial code CO-109 mean on a medical bill?

CO-109 means the claim went to a plan that is not the one on the hook for it. The plan is not saying no to the care; it is saying this one is not ours. It turns up when the billing office used an old card, sent the claim to the wrong part of a plan, or billed a commercial plan for care that belongs to a different program. The fix is almost always administrative, and once the right plan gets the claim it usually processes normally. Meanwhile the CO letters keep the amount on the provider's side of their contract, not on yours.

What should I watch out for with Denial code CO-109?

• Give the billing office a copy of the front and back of the card that was good on that date
• Ask which plan and member number the claim was sent to, then compare that against your coverage
• Ask the provider to refile with the correct plan instead of billing you while the claim sits unpaid