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MA27 Remark Code: Invalid Entitlement Number or Name

MA27 means the entitlement number, which is the patient's Medicare or member ID, or the name shown on the claim is missing, incomplete, or invalid. The payer could not match the claim to an entitled beneficiary.

Quick facts

Code
MA27 (RARC MA27)
Status
Active In use since January 1, 1997; last modified February 28, 2003.
Code set
Remittance Advice Remark Codes (RARC)
Group codes
  • CO (Contractual Obligation): The provider needs to correct the identifying data. The patient should not be billed for a claim returned for this reason.
Official description
Missing/incomplete/invalid entitlement number or name shown on the claim.
X12 Remittance Advice Remark Codes, retrieved September 25, 2026
Last verified
against the official X12 list.

What MA27 means

Every claim has to identify an entitled person. MA27 says the combination of ID and name you sent did not work: the entitlement number was missing or malformed, or the name did not match the record for that number. For Medicare claims, the entitlement number is the Medicare Beneficiary Identifier.

This is a data problem at the front of the claim. The services themselves were not evaluated.

Common causes

  • A transposed or incomplete character in the member ID in box 1a.
  • An old identifier used after the patient received a new card.
  • The patient’s name entered differently from the card, such as a nickname or a missing hyphen.
  • The ID belongs to a spouse or another family member.

How to fix it

  1. Check the card and eligibility response. Compare the ID and name with what you billed.
  2. Correct box 1a and the name fields. Enter the ID and name exactly as the payer records them.
  3. Resubmit. Send a corrected claim; if the original was processed, use resubmission code 7 in box 22 per payer rules.
  4. Contact the payer if the ID and name look right but still fail to match.

How to prevent it

Scan or copy the card at every visit and verify eligibility before billing. A Claims Validator can flag ID formats that cannot be valid before submission. See also claim rejection vs. denial.

Codes that may appear with MA27

  • CO-16 (Claim/service lacks information or has submission/billing error(s).): The claim lacks information needed for adjudication, with MA27 pointing to the ID or name.
  • CO-31 (Patient cannot be identified as our insured.): The patient cannot be identified as the payer's insured.
  • CO-140 (Patient/Insured health identification number and name do not match.): The patient or insured ID and name do not match.
  • MA21 (SSA records indicate mismatch with name and sex.): Name and sex do not match Social Security records.
  • MA36 (Missing/incomplete/invalid patient name.): The patient name is missing or invalid, without reference to the ID.
  • MA61 (Missing/incomplete/invalid social security number.): The Social Security number is missing or invalid.

MA27 FAQ

What is an entitlement number?

It is the identifier showing the patient is entitled to benefits. For Medicare, that is the Medicare Beneficiary Identifier on the patient's card.

Where does the ID go on a CMS-1500?

Box 1a holds the insured's ID number, and boxes 2 and 4 hold the patient and insured names.

What if the patient has a new Medicare card?

Use the identifier on the current card. Old identifiers may no longer be accepted, so update the patient's record.