Remark Code M81 on Your EOB — Meaning & What to Do

Remittance Advice Remark Code (RARC)

What remark code M81 means: A required diagnosis code is missing.
What to do about remark code M81: Ask the provider's billing office to explain or correct this, and resubmit if needed.

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 M81.

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Frequently asked questions about Remark code M81

What does remark code M81 mean on my EOB?

A required diagnosis code is missing.

What should I do about remark code M81?

Ask the provider's billing office to explain or correct this, and resubmit if 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.