CO-16 Denial Code
What it means
Your claim was denied because something was missing or entered wrong - not because the care isn't covered. It's an administrative/paperwork problem.
Why it happens
A required field, code, or attachment was missing or didn't match (often a data-entry or coding mistake by the billing office).
What to do
Look for the paired remark code (it names the exact missing item). Ask your provider's billing office to correct and resubmit a corrected claim - this often fixes it without a formal appeal. Highest overturn rate of any denial type.
Can you appeal it?
Yes - but a corrected resubmission is usually faster.
Official description
Claim/service lacks information or has submission/billing error(s); usually paired with a remark code (e.g., N479, MA130).
Decode your full denial letter
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Decode your full denial letterRelated codes
- MA130 - A remark code meaning the claim had bad/missing info. Importantly, you can't app...
- N479 - A remark code (pairs with a denial like CO-16): the insurer needs the EOB from y...
- CO-252 - The insurer needs extra paperwork (like medical records or notes) before it can ...
- CO-18 - The insurer thinks this exact claim was already submitted, so it rejected the se...