Denial Code 243 (CO-243, PR-243) — Meaning & What to Do

Claim Adjustment Reason Code (CARC)

What denial code 243 means: Services aren't authorized by network or plan providers.
What to do about denial code 243: If you believe this is wrong, you can appeal with supporting notes from your doctor.

CO-243 vs PR-243 vs OA-243: what the prefix means

Code on your EOBWhat the prefix meansWho typically pays
CO-243Contractual obligation — the provider writes the amount offUsually not the patient
PR-243Patient responsibilityThe patient
OA-243Other adjustmentOften another payer or plan

The prefix tells you who is expected to absorb the amount; the number (243) tells you why.

Seeing denial code 243 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 243

What does denial code 243 mean on my EOB?

Services aren't authorized by network or plan providers.

What should I do about denial code 243?

If you believe this is wrong, you can appeal with supporting notes from your doctor.

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.