N249 Remark Code — Missing/Incomplete/Invalid Assistant Surgeon Primary Identifier
N249 is a Remittance Advice Remark Code (RARC) that appears alongside a CARC (usually CO-16) to explain that the assistant surgeon NPI is missing, incomplete, or invalid on the claim. This code is triggered when a surgical claim includes an assistant surgeon but the NPI for that assistant surgeon is not properly entered, is formatted incorrectly, or the assistant surgeon is not enrolled with the payer.
Quick Answer
N249 means the assistant surgeon NPI is missing or invalid on the claim. This is a remark code (RARC), not a denial code — it appears alongside a CARC like CO-16 to explain the specific reason. To resolve it, verify the assistant surgeon NPI is correct and enrolled with the payer, add it to the correct field on the claim, and resubmit as a corrected claim.
Official Definition
Missing/incomplete/invalid assistant surgeon primary identifier.
What This Code Means
N249 is a Remittance Advice Remark Code (RARC) that appears alongside a CARC (usually CO-16) to explain that the assistant surgeon NPI is missing, incomplete, or invalid on the claim. This code is triggered when a surgical claim includes an assistant surgeon but the NPI for that assistant surgeon is not properly entered, is formatted incorrectly, or the assistant surgeon is not enrolled with the payer.
Status
Pending InvestigationRecommended Action
Same standard code · different claim context
How N249 can be investigated across specialties
CARCs and RARCs are not separate code sets for radiology, gastro, hospital, or professional billing. The code meaning stays standardized; the claim fields, documentation, payer rules, and next checks change by setting.
Professional / Office
Check CMS-1500/837P fields, rendering/billing NPI, diagnosis, modifier, place of service, authorization, and payer policy.
Hospital / Facility
Check UB-04/837I bill type, revenue code, status, inpatient/outpatient rules, authorization, and line-level ERA detail.
Radiology
Check 26/TC component billing, imaging authorization, medical necessity, site of service, same-day edits, and referring provider data.
Gastroenterology
Check procedure relationships, screening vs diagnostic context, modifiers, pathology/anesthesia relationships, authorization, and payer edits.
Behavioral Health
Check provider credential, behavioral-health carve-out, authorization, units/time, telehealth, place of service, and plan-specific rules.
Therapy / Rehab
Check therapy modifiers, timed units, benefit limits, authorization, plan of care/documentation, and NCCI/payer edits.
DME / Supplies
Check HCPCS, modifiers, same/similar equipment, medical necessity, proof of delivery, authorization, and supplier enrollment.
Lab / Pathology
Check CLIA, ordering/referring data, diagnosis support, frequency, panel bundling, specimen/documentation, and payer medical policy.
Financial Impact
Should This Go to Coding?
Do not send every denial to Coding. Coding is appropriate only when the resolution requires coding judgment rather than an administrative or payer follow-up action.
Send to Coding When
Do Not Send to Coding When
Simple rule: If you would have to choose, change, or defend a CPT/HCPCS, ICD-10, modifier, code pair, NCCI edit, or documentation-to-code decision, Coding should review it.
Corrected Claim, Reconsideration, Appeal, or Something Else?
Use the ERA/EOB, RARC, payer portal, policy, claim history, and internal workflow to decide between corrected claim, reconsideration, appeal, coding review, payer follow-up, patient responsibility, or adjustment.
Should I Adjust This Balance?
Treat the balance as recoverable until research shows otherwise. The goal of insurance collections is to resolve the denial and obtain payment when a valid recovery path exists.
Collections rule: A denial code by itself does not automatically mean write-off. Work the claim for payment first when a valid recovery path exists.
What Should My Account Note Say?
4-Part Note Formula
WHAT HAPPENED + WHAT YOU REVIEWED/DID + WHY THAT ACTION WAS CORRECT + WHAT HAPPENS NEXT
General Denial Note
REVIEWED ERA/EOB FOR N249. PAYER PROCESSED/DENIED $[AMOUNT] DUE TO [DENIAL REASON + CARC/RARC]. VERIFIED [PORTAL/ELIGIBILITY/CLAIM HISTORY/POLICY/CODING/AUTHORIZATION]. [ACTION TAKEN] BECAUSE [WHY THIS ACTION IS SUPPORTED]. REMAINING BALANCE $[BALANCE]. WILL FOLLOW UP IN [TIMEFRAME] OR NO FURTHER PAYER ACTION REQUIRED.
Adjustment Note
REVIEWED ERA/EOB FOR N249. PAYER APPLIED $[AMOUNT] AS [CONTRACTUAL/NONPAYABLE REASON]. VERIFIED FINAL ADJUDICATION, [CONTRACT/POLICY/CODING REVIEW], AND NO ADDITIONAL RECOVERY PATH. ADJUSTED/REQUESTED ADJUSTMENT OF $[AMOUNT] PER ORGANIZATIONAL WORKFLOW. REMAINING BALANCE $[BALANCE]. [FOLLOW-UP OR RESOLVED].
Current decision: DO NOT ADJUST YET. Do not document an action you did not actually perform. Do not say a payment was posted unless you personally posted it.
How to Investigate
Investigation Checklist
Step-by-Step Workflow
Common Causes
Step-by-Step Resolution
Appeal Guidance
Appeal Grounds
The assistant surgeon NPI was valid and enrolled but was inadvertently omitted or entered incorrectly on the original claim.
Appeal Letter Template
We are appealing the N249 remark (with CO-16) for [procedure], DOS [date]. The assistant surgeon NPI was inadvertently omitted from the original claim. The assistant surgeon, Dr. [name] (NPI [number]), is enrolled with [payer]. Attached is the corrected claim with the assistant surgeon NPI. We request reprocessing.
Required Documentation Checklist
Prevention Strategies
Real-World Examples
Medicare — Assistant Surgeon NPI Omitted
WonA surgical claim was submitted with an assistant surgeon but the NPI was left off the claim. Medicare denied with CO-16 + N249.
Verified the assistant surgeon NPI in the NPI registry, confirmed enrollment in PECOS, added the NPI to the corrected claim (frequency type 7), and resubmitted. Paid within 10 days.
UHC — Assistant Surgeon Not Credentialed
Won (delayed)A claim included an assistant surgeon who was not credentialed with UHC. UHC denied with CO-16 + N249.
Submitted the assistant surgeon for credentialing with UHC. Once credentialed (took 45 days), resubmitted the corrected claim with NPI. Paid.
Patient Responsibility
Never bill the patient for N249. The issue is a missing or invalid provider identifier on the claim.
Payer-Specific Notes
Medicare requires the assistant surgeon NPI in the 835/837 claim. Verify the assistant surgeon is enrolled in PECOS and linked to the billing NPI. Medicare will deny assistant surgeon services if the NPI is not on the claim or if the provider is not enrolled.
UHC requires the assistant surgeon NPI on the claim. Verify the assistant surgeon is credentialed with UHC. Check the UHC provider portal to confirm enrollment status before resubmitting.
Aetna requires the assistant surgeon NPI. Verify the assistant surgeon is in Aetna network. Some Aetna plans require pre-authorization for assistant surgeons — check the plan requirements.
Cigna requires the assistant surgeon NPI in the proper field. Verify enrollment on the Cigna provider portal.
State Medicaid programs require the assistant surgeon NPI. Verify enrollment in the state Medicaid portal. Some states require a separate assistant surgeon enrollment.
Frequently Asked Questions About N249
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Always verify guidance with official payer policies, CMS guidance, coding guidelines, and applicable regulations.
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