Denial Code 27 (CO-27, PR-27) — Meaning & What to Do

Claim Adjustment Reason Code (CARC)

What denial code 27 means: Coverage had ended when this service was provided.
What to do about denial code 27: If your coverage was actually active, contact your insurer to correct the eligibility dates.

CO-27 vs PR-27 vs OA-27: what the prefix means

Code on your EOBWhat the prefix meansWho typically pays
CO-27Contractual obligation — the provider writes the amount offUsually not the patient
PR-27Patient responsibilityThe patient
OA-27Other adjustmentOften another payer or plan

The prefix tells you who is expected to absorb the amount; the number (27) tells you why.

Seeing denial code 27 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 27

What does denial code 27 mean on my EOB?

Coverage had ended when this service was provided.

What should I do about denial code 27?

If your coverage was actually active, contact your insurer to correct the eligibility dates.

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.