Denial Code OA-23 — Coordination of Benefits — How to Navigate It

Denial Code OA-23 involves two insurance plans. Submit to the primary insurer first — here is how coordination of benefit works.

4
 min. read
June 25, 2026
Denial Code OA-23 — Coordination of Benefits — How to Navigate It

What Does Denial Code OA-23 Mean?

Denial code OA-23 means your claim was denied or adjusted because of coordination of benefits — you have more than one health insurance plan, and this insurer is indicating that another plan should be paying first or that the payment from the primary insurer satisfies the claim.

The "OA" prefix stands for "Other Adjustment" — it is neither a CO (contractual obligation) nor a PR (patient responsibility) code.

How Coordination of Benefits Works

When a patient has two health insurance plans, federal and state rules determine which plan pays first (primary) and which pays second(secondary). The secondary plan then coordinates to cover any remaining patient responsibility after the primary plan pays.

Common coordination of benefits situations:

  • A patient covered by both an employer plan and a spouse's employer plan
  • A child covered by both parents' plans
  • A Medicare beneficiary who also has employer coverage or a supplemental plan
  • A patient covered by both Medicaid and a commercial insurer

Why OA-23 Denials Happen

Primary insurance information not submitted

The claim was sent to the secondary insurer without first being processed by the primary insurer.

Incorrect primary/secondary designation

The insurer believes it should be the secondary payer but the claim was submitted as if it were primary.

The primary insurer's payment was not included

The claim was submitted to the secondary insurer but the explanation of benefits from the primary insurer was not attached.

The coordination of benefits information on file is outdated

Your insurer has outdated information about your other coverage.

How to Resolve an OA-23 Denial

  • Confirm which insurer should be primary and which should be secondary under applicable coordination of benefits rules
  • Submit the claim to the primary insurer first if you have not already done so
  • Once the primary insurer processes the claim, submit the secondary claim with the primary insurer's EOB attached
  • If the designation of primary and secondary is incorrect, contact both insurers to update your coordination of benefits information

How ClaimCompass Helps

ClaimCompass analyzes your OA-23 denial and identifies the specific coordination of benefits issue and next steps.

Upload your denial at myclaimcompass.ai for a free analysis.

Frequently Asked Questions

Which plan is primary when both spouses have employer coverage?

Generally, each person's own employer plan is primary for themselves. For covered dependents, the birthday rule typically applies — the plan of the parent whose birthday falls first in the calendar year is primary.

Is Medicare always primary?

Not always. If a person has Medicare and employer coverage from an employer with 20 or more employees, the employer plan is typically primary and Medicare is secondary.