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RARC N31 · Remittance Advice Remark Code

RARC N31 Remark Code: Missing/incomplete/invalid prescribing provider identifier

Reviewed by QuickIntell RCM Editorial Team · Last reviewed

Updated

Not an ICD-10 code. RARC N31 is a remittance-advice remark code published by X12 and carried on the 835 LQ segment. Any ICD-10 code with the same letters and digits (e.g., ICD-10 M15 osteoarthritis, N130 other urinary tract disorders) is a separate, unrelated code set used in diagnoses on the 837. Confirm the context before acting on this page.

TL;DR

RARC N31 (X12 Missing/incomplete/invalid prescribing provider identifier). Commonly paired with CARC 16, CARC 183. RARC N31 flags missing/invalid prescribing-provider NPI — common on pharmacy/DMEPOS claims.

Official X12 description

“Missing/incomplete/invalid prescribing provider identifier.”

Source: X12 Remittance Advice Remark Codes. X12 publishes and maintains the RARC set; always verify against the current release before building a claim workflow.

Paired CARC codes

RARC N31 almost never appears alone — it accompanies one of the CARCs below on the same 835 remittance line. Fix the CARC and the RARC typically clears; the RARC alone is informational.

Paired CARCWhat the CARC means
CARC 16Claim/service lacks information or has submission/billing error(s).
CARC 183The referring provider is not eligible to refer the service billed.
CARC 206National Provider Identifier - missing.

What RARC N31 actually means

RARC N31 flags missing/invalid prescribing-provider NPI — common on pharmacy/DMEPOS claims. Correct and rebill.

Common root causes

  • Prescribing NPI blank/invalid.

Prevention checklist

  • Prescriber-NPI automation on e-prescribing.

Resolution & appeal strategy — step by step

Because RARC N31 is supplemental to a CARC, the resolution path usually starts by fixing the underlying adjustment reason. A formal appeal of the RARC alone is rarely necessary.

  1. 1Correct and rebill.
Sample reconsideration language referencing RARC N31
[Provider letterhead] Re: Reconsideration — Claim #{claim_number}, CARC 16 / RARC N31 Member: {member_name} · Member ID: {member_id} Date(s) of Service: {dos} The 835 remittance on {remittance_date} carried RARC N31: "Missing/incomplete/invalid prescribing provider identifier." We request reconsideration. The attached documentation rebuts the remark code: 1. [State the fact that rebuts the remark — authorization number, primary 835, modifier rationale, LCD citation, etc.] 2. [Reference the paired CARC and the corresponding fix] 3. [Attach the supporting document listed in step 1] Attached: {list supporting documents} Please process this line under the member's benefits. Contact the billing office at {provider_phone} for questions. Sincerely, {billing_manager_name}, {credentials}

Edit the bracketed fields before sending. Payer-specific reconsideration forms are often required — check the provider portal first.

How common is RARC N31?

Platform frequency
Pending ETL

Platform frequency ranks publish once the anonymized denial-rate pipeline reaches the publication threshold (strategy §12 Phase 2).

How QuickRCM handles RARC N31

QuickRCM reads RARC N31 alongside its paired CARC in the 835 LQ segment and routes the line to the correct worker queue with the right documentation already attached:

  • Denial routing rules tuned to the CARC+RARC pair — the paired combination tells QuickRCM which documentation the payer will accept.
  • Reconsideration template for this exact remark code pulls the supporting facts from the claim automatically.
  • Pre-submission scrubs that catch the preventable drivers surfaced on this page before the 837 leaves the clearinghouse.
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Frequently asked questions — RARC N31

What does RARC N31 mean?

RARC N31 is an X12 Remittance Advice Remark Code. The official X12 definition is: "Missing/incomplete/invalid prescribing provider identifier." It is supplemental to a Claim Adjustment Reason Code (CARC) on the same 835 line.

Which CARC is paired with RARC N31?

RARC N31 is most commonly paired with CARC 16, CARC 183, CARC 206. The CARC is the financial adjustment reason; the RARC is the informational remark. Fix the paired CARC first — the RARC usually clears with the corrected claim.

How do I resolve a RARC N31 remark on a remit?

Start from the root cause: Prescribing NPI blank/invalid. First step: Correct and rebill. Because RARCs are supplemental, the resolution is almost always to address the paired CARC rather than appeal the RARC alone.

Where does RARC N31 appear on the 835 ERA?

RARC N31 is carried on the 835 Loop 2110 LQ segment alongside the CARC in the CAS segment of the same service line. The code and its X12 description also print on the paper EOB in the "Remark Code" or "Remark" column next to the corresponding denial or adjustment reason.

Is RARC N31 the same as ICD-10 code N31?

No. RARC N31 is a remittance-advice remark code published by X12 and carried on the 835. Any ICD-10 code with the same letters and digits is a diagnosis code on the 837 HI segment — a completely different code set maintained by the WHO/CMS. Use the transaction context (835 = RARC; 837 = ICD-10) to disambiguate.

Disclaimer

This page is operational reference for medical-billing professionals. It is not legal, clinical, or contractual advice. X12 code descriptors are maintained by the X12 External Code Lists; always verify against the current X12 release and the payer's own published policy before submitting or appealing a claim.