How do I resolve a CO-16+N105 denial?

Verify patient's RRB beneficiary status: Confirm the patient is covered under Railroad Retirement Board benefits to ensure N105 guidance is accurate for this beneficiary Prepare claim for Palmetto GBA submission: Format claim for RRB carrier Palmetto GBA; submit paper claims to P.O. Box 10066, Augusta, GA 30999, or call 888-355-9165 for EDI electronic submission requirements Write off the CO adjustment and submit to correct payer: Post the contractual write-off from the incorrect payer and submit a new original claim to Palmetto GBA as the correct RRB carrier

835 Denial Combination

CO-16+N105

Contractual Obligation · Claim-Level Adjustment

Missing/Invalid Information

What This Combination Means

The claim was submitted to the wrong payer because the beneficiary is covered by the Railroad Retirement Board (RRB), not the payer that processed this denial. The RARC N105 specifies that the claim should have been sent to Palmetto GBA, the RRB carrier. The CO group code indicates the provider must write off this adjustment but may resubmit to the correct payer.

Financial Responsibility

provider writeoff

The provider must write off this adjustment from the incorrect payer per contractual obligation, but may recover payment by submitting the claim correctly to Palmetto GBA for RRB processing.

N/A

Appeal Success

2-4 weeks (corrected submission to proper payer)

Avg. Resolution

Medium

Difficulty

Appealable

Step-by-Step Resolution

Steps tailored specifically to this CO-16+N105 combination — not generic advice.

Not Appealable:This is a routing error to the wrong payer, not a coverage determination; the resolution is to submit to the correct RRB carrier, not appeal.

1
Verify patient's RRB beneficiary status
Confirm the patient is covered under Railroad Retirement Board benefits to ensure N105 guidance is accurate for this beneficiary
2
Prepare claim for Palmetto GBA submission
Format claim for RRB carrier Palmetto GBA; submit paper claims to P.O. Box 10066, Augusta, GA 30999, or call 888-355-9165 for EDI electronic submission requirements
3
Write off the CO adjustment and submit to correct payer
Post the contractual write-off from the incorrect payer and submit a new original claim to Palmetto GBA as the correct RRB carrier

Specialty Context

How CO-16+N105 typically presents across different practice types.

Dental

Verify if RRB dental benefits apply; some RRB coverage may have separate dental carrier instructions beyond Palmetto GBA medical claims

Medical

Common for Medicare-age patients who worked for railroad companies; always verify RRB status before assuming Medicare as primary

Behavioral Health

RRB mental health benefits may have specific authorization requirements through Palmetto GBA; confirm coverage parameters before resubmission

Individual Code References

View the standalone definition for each code in this combination.

CARC 16 RARC N105

Medicare Contractor Guidance for CARC 16

FCSO + Noridian + uhc + aetna + bcbs_az

This RUC is received when a claim is submitted with missing, incorrect, or invalid information. For details pertaining to your claim, please refer to the remittance advice remark codes (RARCs) on the remittance advice (RA).

How to Prevent CARC 16 Denials

✓
Review the RARC on the remittance advice to identify which specific field has the error.
✓
Per Medicare guidelines, claims must be filed no later than 12 months after the date of service. RUCs are not considered filed/submitted.

CMS guidelines for completion of form CMS-1500 in the Medicare Claims Processing Manual (100-04), Chapter 26SPOTFee Schedule Lookup ToolCMS laboratory demographics lookupModifier lookup toolNoridian Medicare PortalNMPIVRSame or SimilarPECOSPDAC

Need to resolve this denial?

Get a complete resolution plan with appeal guidance for this exact combination in seconds.

Generate a free resolution plan & appeal letter →

Synthesized from official definitions — not from training data

Was this helpful?

← Back to Combo Lookup Browse All Codes →