Denial Code 131 (CO-131, PR-131) — Meaning & What to Do

Claim Adjustment Reason Code (CARC)

What denial code 131 means: A negotiated or contractual discount was applied.
What to do about denial code 131: For in-network care this is a normal write-off, not your cost.

CO-131 vs PR-131 vs OA-131: what the prefix means

Code on your EOBWhat the prefix meansWho typically pays
CO-131Contractual obligation — the provider writes the amount offUsually not the patient
PR-131Patient responsibilityThe patient
OA-131Other adjustmentOften another payer or plan

The prefix tells you who is expected to absorb the amount; the number (131) tells you why.

Seeing denial code 131 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 131

What does denial code 131 mean on my EOB?

A negotiated or contractual discount was applied.

What should I do about denial code 131?

For in-network care this is a normal write-off, not your cost.

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.