835 Denial Combination

CO-16+N335

CO

Contractual Obligation · Service-Line Level Adjustment

Missing Information

What This Combination Means

The payer denied this claim due to a missing, incomplete, or invalid referral date required for processing. This is a contractual adjustment where the provider cannot collect from the patient, but the claim can be corrected and resubmitted if the referral date information is obtained and validated.

Financial Responsibility

provider writeoff

The provider must write off the denied amount per contract terms. Once corrected with valid referral date information, the claim may be reprocessed for payment.

N/A

Appeal Success

7-14 days (claim correction cycle)

Avg. Resolution

Medium

Difficulty

No

Appealable

Step-by-Step Resolution

Steps tailored specifically to this CO-16+N335 combination — not generic advice.

Not Appealable:This is a correctable billing error requiring claim correction and resubmission, not an appeal process, as the claim lacks required referral date information.
  1. 1

    Verify referral documentation in patient record

    Locate the original referral authorization to identify the referral date that should have been submitted with the claim

  2. 2

    Validate referral date format and completeness

    Ensure the referral date is complete (MM/DD/YYYY format), matches payer requirements, and falls within appropriate timeframes relative to service dates

  3. 3

    File corrected claim with accurate referral date in appropriate field

    Submit a corrected claim (Claim Frequency Code 7) including the valid referral date in the designated referral information fields per payer specifications

Specialty Context

How CO-16+N335 typically presents across different practice types.

Dental

Specialty dental services (orthodontics, oral surgery, periodontics) often require referrals from general dentists; ensure referring dentist information and referral date are captured at scheduling

Medical

Common for specialist services, diagnostic imaging, DME, and outpatient procedures requiring PCP referrals under managed care plans; referral date must precede or match service date

Behavioral Health

Applicable to therapy services, psychiatric consultations, and substance abuse treatment requiring referrals from PCPs or case managers; ensure referral date is documented in authorization tracking systems

Individual Code References

View the standalone definition for each code in this combination.

CARC 16RARC N335

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

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Synthesized from official definitions — not from training data

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