OwedInsurance appeals

Denial codes

CO-109

Sent to the wrong insurer

The claim went to the wrong plan or Medicare contractor. The provider needs to send it to the right one.

Official meaning (X12 code 109): Claim/service not covered by this payer/contractor. You must send the claim/service to the correct payer/contractor.

Who pays

CO-109. Contractual obligation: the provider's contract with your plan makes this the provider's write-off. An in-network provider generally can't bill you for a CO amount.

What to do

  1. Give the provider your current insurance card.
  2. Ask them to bill the correct payer.
  3. Don't pay while it's rebilled.

If you appeal

The plan thinks another insurer should pay first. Usually a short call or form telling them you have no other coverage, or which plan is primary, reopens the claim.

What the appeal asks for: Reprocess this claim; I have updated coordination-of-benefits information showing this plan is primary.

Deadlines for the first appeal

employer plan
180 days from the notice
ACA Marketplace plan
180 days from the notice
Medicare Advantage plan
65 days from the notice
Original Medicare
120 days from the notice
Medicaid
60 days from the notice

The date printed on your notice controls. Urgent care can be appealed on an expedited (72-hour) basis.

What the data show

11.5%Only 11.5% of denied Medicare Advantage prior authorization requests were appealed in 2024. KFF, 2024 data
80.7%80.7% of appealed Medicare Advantage prior authorization denials were partially or fully overturned in 2024. KFF, 2024 data
<1% (262,982 appeals)Fewer than 1% of denied in-network marketplace claims were appealed in 2024 (at least 262,982 appeals). KFF, 2024 data
66% upheldInsurers upheld 66% of denials on internal appeal in 2024 (165,863 denials). KFF, 2024 data

Averages across all denials; not a prediction for yours.

Not sure this applies to you?

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General information, not legal or medical advice. Owed is a document-preparation and sending service, not a law firm.