835 Denial Combination

CO-16+MA66

CO

Contractual Obligation · Service-Line Level Adjustment

What This Combination Means

Item billed was missing or had an incomplete/invalid procedure code

N/A

Appeal Success

7-14 days

Avg. Resolution

Medium

Difficulty

No

Appealable

Step-by-Step Resolution

Steps tailored specifically to this CO-16+MA66 combination — not generic advice.

  1. 1

    Correct claim and resubmit claim with a valid procedure code listed on the PDAC website

Specialty Context

How CO-16+MA66 typically presents across different practice types.

Dental

Medical

Behavioral Health

Individual Code References

View the standalone definition for each code in this combination.

CARC 16RARC MA66

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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