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CO-D21 - Denial Journal
CARC

CO-D21

What This Code Means

This (these) diagnosis(es) is (are) missing or are invalid. This code was deactivated by X12 (as of 06/30/2007).

How to Resolve or Appeal

  1. This is a historical/deactivated code — no longer used on current claims. If seen on an old remittance, refer to the replacement code noted above where available.

More Denial Codes to Check

RARC M58 RARC N95 This provider type/specialty may not bill this service RARC M49 RARC MA43 CARC CO-59 Processed based on multiple or concurrent procedure rules RARC MA114 RARC MA66 RARC N31 RARC M56 CARC CO-P9 RARC MA105 RARC M127 RARC N58

Educational reference only — not medical or legal advice. Always confirm code usage and appeal rights with the specific payer.

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