RARC N522: Duplicate of a Claim Processed as a Crossover Claim
RARC N522 means the claim is a duplicate of one already processed, or to be processed, as a crossover claim — the primary payer automatically forwarded it to the secondary, and your manual secondary claim doubled it. It rides with CO-18 or OA-18. The fix is usually no action: let the crossover pay and stop manually billing the secondary.
- Type
- Informational (supplemental)
- Usually paired with
- CO-18, OA-18 (duplicate)
- Fixable?
- Usually no fix needed — crossover already handled it
- Typical fix
- Stop manual secondary billing; let the crossover adjudicate
What does remark code N522 mean?
Official X12 text: "Duplicate of a claim processed, or to be processed, as a crossover claim." The secondary payer already received the claim automatically from the primary through the crossover system, so the copy you sent manually is a duplicate of the one in flight. This is a housekeeping remark, not a coding error.
ERA mini-example: 99214 (established E/M) pays $92.00 at Medicare, which crosses the claim to the Medigap plan. Your billing team also drops a manual secondary claim; the Medigap plan returns it with CO-18 and N522 as a duplicate of the crossover it already holds and is paying.
Which denial code does N522 come with?
Almost always a duplicate CARC — CO-18 or OA-18 (exact duplicate claim or service). The CARC says "we already have this"; N522 clarifies that the original arrived through crossover, not through another submission of yours. If you also see coordination of benefits remarks, the root issue is COB routing. Confirm the pairing in the denial code lookup.
How do you handle an N522 denial?
- Check the primary payer's remit for a crossover remark (on Medicare, MA18) confirming the claim was forwarded.
- If the crossover fired, take no action — wait for the crossover claim to adjudicate and post that payment.
- Do not resubmit the secondary; a second manual claim only produces another duplicate.
- If, after a reasonable wait, no crossover claim ever adjudicates and the secondary has nothing on file, bill the secondary once with the full primary payment detail.
How do you prevent N522?
Know which of your secondary relationships cross over automatically — most Medigap and many Medicaid-as-secondary pairs do — and turn off manual secondary claim generation for those. Confirm the supplemental plan is on the beneficiary's crossover file so the forward actually triggers. Give the crossover a set number of days to adjudicate before anyone bills the secondary by hand, and reconcile electronic remittance advice so posters can see the crossover already paid.
Frequently asked questions
Usually nothing. N522 means the primary payer already forwarded the claim to the secondary through the crossover process, so your manually submitted secondary claim is the duplicate. Wait for the crossover claim to adjudicate and pay. Acting on N522 by resubmitting again only creates another duplicate and delays the real payment.
Look at the primary payer's remittance advice — a crossed-over claim shows a remark that the claim was forwarded to the supplemental payer (often MA18 on Medicare remits). N522 on your secondary confirms the receiving payer already has it. If neither the primary remit nor the secondary shows the crossover, then the automatic forward may not have fired and you may still need to bill.
Only if you can confirm the crossover did not actually process — no crossover remark on the primary, nothing on file at the secondary after a reasonable wait. In that case bill the secondary once with the full primary payment detail. Duplicate submissions before confirming the crossover failed are the usual reason N522 keeps reappearing.
Sources & further reading
Reviewed by the ImmediCare Solutions RCM team
Certified billers and coders handling claims across 50+ specialties nationwide. This entry is reviewed against current payer policy and CMS rules. Last review: Jul 5, 2026.
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