N479 Denial Code
What it means
A remark code (pairs with a denial like CO-16): the insurer needs the EOB from your primary plan before it will pay.
Why it happens
You have other/primary coverage and its EOB wasn't attached to the claim.
What to do
Get the primary insurer's EOB and have the provider resubmit it with the claim to the secondary payer.
Can you appeal it?
Resolved by submitting the primary EOB.
Official description
Missing Explanation of Benefits (coordination of benefits or Medicare secondary payer).
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