N479 remark code

Remittance advice remark code N479. Remark codes add detail to the reason code on the same claim line.

Other payer EOB missing for COB

Unofficial reference. This is our own plain-English explanation, not the official code text. Payer rules differ. Verify with the payer and the official X12 code list. AlphaPrefix is not affiliated with X12, CMS or any payer. Data last updated Nov 11, 2026.

What N479 means

The explanation of benefits needed to coordinate benefits with another payer was not received with the claim.

N479 is used when the payer is processing as secondary, or checking whether it should be primary, and needs to see the other payer's remittance. Without it the payer cannot calculate its share.

It often supports reason code 16 or 22. On electronic claims, populating the other payer's paid amount and adjustments usually satisfies the requirement.

Common causes

• The secondary claim was sent before the primary payer finished processing.
• Other payer adjudication details were missing from the electronic claim.
• A paper EOB attachment was not linked to the claim.

What to do next

1. Get the primary payer's remittance for the same service dates.
2. Add the other payer adjudication data or attach the EOB and resubmit.
3. Hold secondary claims until the primary remittance has posted.

Related codes

• N4 (remark code) Prior payer EOB missing or invalid
• N245 (remark code) Other insurance plan details invalid
• 22 (reason code) Another payer may be primary