835 Denial Combination

CO-16+N416

CO

Contractual Obligation · Claim-Level Adjustment

Missing/Invalid Information

What This Combination Means

The claim contains a billing error related to service frequency limits: the billed service is only covered once every three years, and this instance exceeds that contractual limitation. The RARC clarifies that the submission error referenced in CARC 16 is specifically a frequency violation, not a missing information issue. The provider must contractually write off the adjustment amount.

Financial Responsibility

provider writeoff

The provider is contractually obligated to write off the denied amount due to frequency limits established in the payer agreement. The patient cannot be billed for this service.

N/A

Appeal Success

Immediate (write-off)

Avg. Resolution

Easy

Difficulty

No

Appealable

Step-by-Step Resolution

Steps tailored specifically to this CO-16+N416 combination — not generic advice.

Not Appealable:Frequency limitations are contractual provisions agreed upon by the provider, and CO adjustments for exceeding these limits are not appealable.
  1. 1

    Verify the service history in payer system or patient's claims record

    Confirm when this service was last performed and paid to validate the 3-year frequency rule was indeed violated

  2. 2

    Document the date of last allowable service in billing notes

    Record the prior service date to prevent future duplicate billings and set a reminder for when the service becomes eligible again

  3. 3

    Apply contractual write-off to patient account

    Adjust off the denied amount with CO-16/N416 notation and ensure no patient statement is generated for this charge

Specialty Context

How CO-16+N416 typically presents across different practice types.

Dental

Commonly applies to preventive services like comprehensive oral evaluations (D0150) or full-mouth radiographs (D0210/D0330) that have multi-year frequency limits in dental plans

Medical

Frequently seen with screening services such as routine colonoscopies, bone density scans (DEXA), or certain preventive imaging that have regulatory or contract-based frequency restrictions

Behavioral Health

May apply to comprehensive psychological evaluations or certain diagnostic assessments that payers limit to once per benefit period or multi-year span

Individual Code References

View the standalone definition for each code in this combination.

CARC 16RARC N416

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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