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.

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.

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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.