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Remittance advice remark code

MA27: Missing, incomplete or invalid Medicare number or name

MA27 means: Missing/incomplete/invalid entitlement number or name shown on the claim. Medicare cannot match the beneficiary: the Medicare Beneficiary Identifier or the name on the claim does not agree with the entitlement record.

MA27 is a remark code, not a reason code

It explains or adds detail to a decision. It does not carry a group code, and it can never on its own make a balance the patient’s responsibility. The claim adjustment reason code on the same remittance line is what actually decides the outcome — read that first, then read this for the detail.

CARC — claim adjustment reason code. What was adjusted, and under which group code.
RARC — remittance advice remark code, like this one. Explanatory only. No group code, no patient responsibility.
Never move a balance to the patient on the strength of a remark code. Find the reason code and read its group code.

What causes it

The old HICN, or a mistyped MBI
Name entered as it appears in the chart rather than exactly as on the Medicare card — a middle initial, a hyphen, a suffix
A new MBI issued after the card was compromised, with the office still using the old one

How to work it

Run a Medicare eligibility check and take the MBI and name exactly as returned; the MAC portals also offer an MBI lookup.
Correct the claim and resubmit. It was returned unprocessable, so there is nothing to appeal.
Watch the timely filing clock — an unprocessable claim does not stop it.

How to stop it recurring

Capture the MBI from an eligibility response at every visit, not from the card image, and re-check when a card is reported lost.

Who does this work

A eligibility & benefits verification seat at $1,700 per seat per month works this queue full time, during your business hours, inside your own system. Every call is logged with the payer reference number and the outcome, and every Friday you get it in writing.

What that seat does →

Codes worked the same way

MA27 is corrected and resubmitted. So are these, which is why a queue sorted by recovery route moves faster than one sorted by code number — the same person, in the same system, with the same evidence to hand, clears all of them in one pass.

CO-16 — Claim lacks information
CO-4 — Modifier and code disagree
CO-11 — Diagnosis and procedure disagree
CO-140 — Member ID and name disagree
CO-5 — Wrong place of service
CO-9 — Diagnosis and age disagree

Specialties that name this among their costliest

These are specialties whose own worst denials include one of this kind. The line under each is the denial they name, quoted from their page so you can see what the link is based on.

Pain Management
Bilateral procedures billed without the correct modifier
Anesthesia
Time units miscalculated from an incomplete anesthesia record
Orthopedics
Modifier 25 denied on an E/M billed the same day as a procedure
Behavioral Health
Telehealth denied for the wrong place-of-service or modifier
Gastroenterology
Screening colonoscopy converted to diagnostic without modifier PT or 33
Dermatology
Modifier 59 on multiple lesion removals rejected as unbundling

What leaving it costs

Working a denied claim costs $57.23 per denied claim in administrative time. Source. At 100 denials a month — an illustration, not a measurement of your practice — that is $5,723 a month, or $68,676 a year, in labour alone.

The figure that makes it worth spending: about 90% of initially denied claims are eventually paid. Source. The reason a denial sits is almost never that nobody knows how to work it — it is that nobody has the hours.

Questions

What does denial code MA27 mean?

Missing/incomplete/invalid entitlement number or name shown on the claim. In plain terms: Medicare cannot match the beneficiary: the Medicare Beneficiary Identifier or the name on the claim does not agree with the entitlement record.

What causes MA27?

The old HICN, or a mistyped MBI. Name entered as it appears in the chart rather than exactly as on the Medicare card — a middle initial, a hyphen, a suffix. A new MBI issued after the card was compromised, with the office still using the old one.

How do you fix a MA27 denial?

Run a Medicare eligibility check and take the MBI and name exactly as returned; the MAC portals also offer an MBI lookup.. Correct the claim and resubmit. It was returned unprocessable, so there is nothing to appeal.. Watch the timely filing clock — an unprocessable claim does not stop it..

Can MA27 be prevented?

Capture the MBI from an eligibility response at every visit, not from the card image, and re-check when a card is reported lost.

What about the codes next to MA27?

MA26 and MA28 are separate codes and this site does not yet cover them. The authoritative list is the X12 Remittance Advice Remark Codes at x12.org/codes/remittance-advice-remark-codes; a code is only described here once its official text, causes and fix have been written and checked.

Code descriptions are the standard X12 claim adjustment reason and remittance advice remark code text. Payer policies differ, and the payer’s own coverage policy governs any individual claim. This page is working guidance, not legal or clinical advice.

Last updated 2026-09-12. This is operational guidance drawn from payer remittance practice, not legal, coding or reimbursement advice. Payer-specific rules vary and change; confirm against the payer’s own policy before acting on a specific claim.

Written by Ibtesam Asif · Last reviewed 2026-09-12

Code descriptions are the standard published text. Everything after them is operational guidance from our own work, and payer policy governs any individual claim.

Other denial codes

Next step

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