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Denial code CO-11: what it means and what to do

Denial code CO-11 on your Explanation of Benefits: The diagnosis on the claim doesn't match the procedure billed.

What CO-11 means

The diagnosis on the claim doesn't match the procedure billed.

CO means contractual obligation: under its contract, the provider is usually responsible for this amount, so an in-network provider generally should not bill you for it.

What to do

Call the provider's billing office and ask them to correct the claim and send it again.

You may not need a formal appeal: a corrected claim is often enough.

Your deadline

Most plans give you 180 days from the denial notice to file an internal appeal. Original Medicare gives 120 days from the Medicare Summary Notice, and Medicare Advantage plans 65 days from their decision. Check the date printed on your letter.

More on this reason: Billing or coding error.

Other denial codes

• CO-50
• CO-197
• CO-198
• CO-15
• CO-16
• CO-18
• CO-97
• CO-4
• CO-29
• CO-96
• CO-204
• CO-119
• CO-167
• CO-55
• CO-242
• CO-22
• CO-109
• CO-27
• CO-26
• CO-31
• CO-45
• PR-1
• PR-2
• PR-3

Sources

1. HealthCare.gov: Internal appeals
2. 29 CFR 2560.503-1, claims procedure for employer health plans