Denial Code 22 (CO-22, PR-22) — Meaning & What to Do

Claim Adjustment Reason Code (CARC)

What denial code 22 means: Another insurance should be billed first (you may have primary coverage elsewhere).
What to do about denial code 22: Confirm which insurance is primary and make sure the correct one was billed first.

CO-22 vs PR-22 vs OA-22: what the prefix means

Code on your EOBWhat the prefix meansWho typically pays
CO-22Contractual obligation — the provider writes the amount offUsually not the patient
PR-22Patient responsibilityThe patient
OA-22Other adjustmentOften another payer or plan

The prefix tells you who is expected to absorb the amount; the number (22) tells you why.

Seeing denial code 22 on your EOB?
A denial code tells you what the payer reported, but it may not tell the whole story. Reviewing your EOB and bill together can help clarify what may need attention.

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Related codes

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Frequently asked questions about Denial code 22

What does denial code 22 mean on my EOB?

Another insurance should be billed first (you may have primary coverage elsewhere).

What should I do about denial code 22?

Confirm which insurance is primary and make sure the correct one was billed first.

Seeing this code on your own EOB?
Upload the EOB, the bill, or both — MD Bill Check reads the codes on your documents, compares them side by side, and flags what's worth questioning. Free, no account needed.

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Last reviewed 2026-07-07 · MDBillCheck Editorial Team. Plain-English explanations are original wording; always verify the specific reason with your insurer.