Remittance Advice Remark Codes (RARC): The Complete Overview
Remittance Advice Remark Codes (RARCs) are the supplemental messages on an ERA that explain an adjustment in detail or convey information the reason code cannot. More than 1,000 exist. Supplemental RARCs name the exact field or document to fix; Alert RARCs, whose text begins with "Alert:", are informational only.
- List owner
- Maintained by CMS, published by X12
- Code count
- 1,000+ active codes
- Two types
- Supplemental (fix this) and Alert (FYI only)
- Update cycle
- 3x per year (spring, summer, fall)
What are Remittance Advice Remark Codes?
RARCs are the second half of every denial message. The CARC gives the category ("claim lacks information"); the RARC gives the specifics ("missing/incomplete/invalid ordering provider primary identifier"). They appear in the LQ and MOA/MIA segments of the 835 ERA and in the remark column of a paper remit. The list is maintained by CMS on behalf of the industry and published by X12, with updates three times a year.
What is the difference between supplemental and Alert RARCs?
Supplemental RARCs explain an adjustment and imply an action: fix the named field, send the named document. Alert RARCs — the official text literally begins with "Alert:" — convey information without an adjustment, like MA15 (your claim was split) or M16 (see our bulletin). Working an Alert code as if it were a denial wastes touches; ignoring a supplemental code guarantees the same denial next month.
Which RARCs show up most often?
| RARC | Plain English | Usual CARC |
|---|---|---|
| MA130 | Claim unprocessable — resubmit new, no appeal | CO-16 |
| N265 / N286 / N290 | Ordering / referring / rendering provider ID problem | CO-16 |
| M51 | Missing or invalid procedure code | CO-16 |
| N706 | Missing documentation | CO-252 |
| MA04 | Secondary claim needs primary payer info | CO-16 |
Example ERA line: 99213 billed $145.00, paid $0.00, CO-16 with N290. The claim went out under the group NPI with no rendering provider in box 24J. One field, one rebill.
How do you work RARCs efficiently?
- Post the CARC, but queue the work by RARC — the RARC is the actual task.
- Translate any unfamiliar code with the denial code lookup.
- Trend your top five RARCs monthly; each maps to one broken front-end step you can fix upstream.
Frequently asked questions
A Remittance Advice Remark Code is a standardized message a payer attaches to an ERA line or claim to explain an adjustment in more detail than the CARC allows, or to pass along information. Example: CO-16 says the claim lacks information; the attached RARC N286 says exactly what is missing — the referring provider identifier.
They mark historical batches, not meaning. M and MA codes originated with Medicare remittance messages and were folded into the national standard; N codes are the ongoing series where new codes are added. Treat the prefix as trivia — an M code is not more or less serious than an N code. The text is what matters.
No. RARCs are supplemental, so many adjustments arrive with a CARC only. The exception: generic CARCs like 16 (claim lacks information) and 252 (attachment needed) require at least one RARC to be usable, and payers are expected to send one. If you receive a bare CO-16 with no remark code, call the payer — you cannot work it blind.
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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