Remark Code MA27 on Your EOB — Meaning & What to Do

Remittance Advice Remark Code (RARC)

What remark code MA27 means: Your Medicare ID number is missing, incomplete, or invalid.
What to do about remark code MA27: Verify your Medicare number with the provider.

Remark codes add detail to a claim decision. They appear alongside the main adjustment codes on your Explanation of Benefits or remittance notice, giving the specific reason behind remark code MA27.

Seeing remark code MA27 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 Remark code MA27

What does remark code MA27 mean on my EOB?

Your Medicare ID number is missing, incomplete, or invalid.

What should I do about remark code MA27?

Verify your Medicare number with the provider.

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.