RARC N598: Health Care Policy Coverage Is Primary
RARC N598 means the payer's records show another health care policy is primary, so it is refusing responsibility as secondary. It usually rides with CO-22 (care may be covered by another payer per coordination of benefits). The fix is to bill the correct primary first, then resubmit the secondary claim with the primary EOB.
- Type
- Informational (supplemental)
- Usually paired with
- CO-22 (and CO-16 on some payers)
- Fixable?
- Yes — when the COB order is corrected
- Typical fix
- Bill the true primary first, then resubmit secondary with EOB
What does remark code N598 mean?
Official X12 text: "Health care policy coverage is primary." The payer you billed believes it sits behind another coverage in the order of benefits. It is not rejecting the service on medical grounds — it is telling you a different health care policy should adjudicate first, so bill that payer before coming back.
ERA mini-example: 99214 (established office visit) billed $185.00 pays $0.00 with CO-22 and N598. The payer's records show the patient\'s spouse\'s plan is primary under the birthday rule. Bill the spouse\'s plan first, then resubmit this claim as secondary with that primary EOB, and the coordinated balance processes.
Which denial code does N598 come with?
Almost always CO-22 (this care may be covered by another payer per coordination of benefits). Some payers instead route it under CO-16 when they treat the claim as unprocessable. On a claim that actually coordinates correctly you would see OA-23 reflecting the prior payer impact. The CARC carries the money message; N598 clarifies the reason is order of benefits. Decode the pairing in the denial code lookup.
How do you fix an N598 denial?
- Determine the true order of benefits — check for a second coverage, apply the birthday rule, employment status, or Medicare Secondary Payer rules as applicable.
- If another plan is genuinely primary, bill that payer first and post its adjudication.
- Resubmit this claim as secondary with the primary EOB and complete coordination of benefits data in the 837 COB loops.
- If this payer really is primary, have the patient update the payer\'s COB file, then resubmit or appeal with proof of the correct order.
How do you prevent N598?
Run a real-time eligibility check (270/271) at registration and confirm the order of benefits for every patient who has more than one coverage. Ask about spouse, employer, and Medicare status up front so the correct primary is on file before the claim goes out. Track N598 by payer: a cluster usually points to intake missing a second coverage or a stale COB record that a quick patient questionnaire will clear.
Frequently asked questions
The payer's coordination of benefits file lists a second coverage it believes should pay first — for example a spouse's plan under the birthday rule, an employer group plan ahead of a retiree plan, or Medicare positioned behind an active-employment group health plan. It is not denying the service; it is saying you billed the wrong payer first. Determine the correct order of benefits and route the claim accordingly.
Then the payer's COB record is stale. Have the patient contact that plan and complete its coordination of benefits questionnaire so the file is corrected to show this coverage as primary. Then resubmit. If the payer confirms the update, the claim will process; a formal appeal with proof of the correct order of benefits may be needed if they resist.
No. N598 arrives under group code CO or OA as a coordination message, not a benefit exclusion, so the amount is not patient responsibility. The right next step is billing the correct primary payer, not the patient. Patient balances only appear after the primary adjudicates and returns a genuine PR amount.
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.
Stop losing revenue to problems like this.
A free billing audit shows exactly where your practice is leaking money — no cost, no commitment.
