RARC MA27: Missing, Incomplete, or Invalid Entitlement Number or Name
RARC MA27 means the entitlement number or name shown on the claim is missing, incomplete, or invalid — on Medicare claims, that is the MBI or the beneficiary name not matching the enrollment file. It rides with CO-16, and the fix is verifying the exact ID and name through eligibility and resubmitting.
- Type
- Informational (supplemental)
- Usually paired with
- CO-16
- Fixable?
- Yes — always
- Typical fix
- Verify MBI/name via eligibility; resubmit exactly as enrolled
What does remark code MA27 mean?
Official X12 text: "Missing/incomplete/invalid entitlement number or name shown on the claim." Medicare could not match the beneficiary you billed to a person in its enrollment file. Either the MBI is wrong, the name does not match, or the two do not belong together.
ERA mini-example: a $185.00 visit for "Bob Smith" denies CO-16 with MA27. Medicare has him as "Robert L Smith Jr" — the front desk keyed the nickname from conversation instead of scanning the card, and the name-match failed. Corrected to the enrollment-file name, the claim pays without argument.
Which denial code does MA27 come with?
Nearly always CO-16 — the claim is unprocessable, not denied on merits, so there is nothing to appeal and everything to correct. Frequently it travels alongside MA130 (unprocessable, resubmit new claim), which tells you the rework path. Confirm your exact combination in the denial code lookup.
How do you fix an MA27 denial?
- Run a 270/271 eligibility check to pull the active MBI and the name exactly as enrolled — including middle initials and suffixes.
- If eligibility cannot find the patient, use the MAC portal MBI lookup with the SSN-based search, or have the patient check their account at medicare.gov.
- Correct the patient record in your PM system first, then resubmit as a new claim (MA27 claims are typically unprocessable, so corrected-claim frequency codes do not apply).
- Watch the timely filing date — unprocessable claims do not protect the original submission date.
How do you prevent MA27?
Scan cards instead of typing, verify eligibility electronically before every visit (not just new patients — MBIs change), and lock registration to the 271 response: name and ID auto-populated from the payer beats anything a human transcribes. Track MA27 by registration user; it is a pure data-entry metric, and coaching the top offender usually halves the volume in a month, protecting your clean-claim rate.
Frequently asked questions
The Medicare Beneficiary Identifier (MBI) — the 11-character alphanumeric ID that replaced SSN-based numbers. MA27 fires when the MBI is mistyped, when a character like the letter O is confused with zero (MBIs never use B, I, L, O, S, or Z), or when the claim carries an old number after CMS reissued the MBI due to identity theft.
The enrollment file, not the card, is the source of truth. Beneficiaries get new MBIs after fraud events, and names change with marriage or corrections — the old card keeps circulating. Run a real-time eligibility check (270/271); it returns the active MBI and the name exactly as Medicare has it, including suffixes like Jr that trip name matching.
The wording is Medicare-flavored ("entitlement number"), and Medicare and Medicare Advantage remits are where you will see it. Commercial payers flag the equivalent problem — bad subscriber ID or name mismatch — with other remarks such as N382 or MA36. The fix logic is identical: bill the ID and name character-for-character as the payer holds them.
Sources & further reading
Reviewed by the ImmediCare Solutions RCM team
Certified billers and coders handling claims across 50+ specialties nationwide. This entry is reviewed against current payer policy and CMS rules. Last review: Jul 5, 2026.
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