Denial Code 256 (CO-256, PR-256) — Meaning & What to Do

Claim Adjustment Reason Code (CARC)

What denial code 256 means: This service isn't payable under a managed-care contract.
What to do about denial code 256: Ask the provider's billing office to explain or correct this, and resubmit if needed.

CO-256 vs PR-256 vs OA-256: what the prefix means

Code on your EOBWhat the prefix meansWho typically pays
CO-256Contractual obligation — the provider writes the amount offUsually not the patient
PR-256Patient responsibilityThe patient
OA-256Other adjustmentOften another payer or plan

The prefix tells you who is expected to absorb the amount; the number (256) tells you why.

Seeing denial code 256 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 256

What does denial code 256 mean on my EOB?

This service isn't payable under a managed-care contract.

What should I do about denial code 256?

Ask the provider's billing office to explain or correct this, and resubmit if needed.

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.