The Complete Insurance Denial Code Library — What Every Code Means
The ClaimCompass Denial Code Library translates every major insurance denial code and tells you exactly what to do.
Denial Code OA-23 involves two insurance plans. Submit to the primary insurer first — here is how coordination of benefit works.

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.
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:
The claim was sent to the secondary insurer without first being processed by the primary insurer.
The insurer believes it should be the secondary payer but the claim was submitted as if it were primary.
The claim was submitted to the secondary insurer but the explanation of benefits from the primary insurer was not attached.
Your insurer has outdated information about your other coverage.
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.
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.
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.