CO-D23
What This Code Means
This dual eligible patient is covered by Medicare Part D per Medicare Retro-Eligibility. This code was deactivated by X12 (as of 01/01/2012).
How to Resolve or Appeal
- 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
Educational reference only — not medical or legal advice. Always confirm code usage and appeal rights with the specific payer.