← All denial codes
CO-55
Recoverability: Low
Procedure/treatment/device deemed experimental or investigational by the payer
The plan classifies the procedure as experimental or investigational and excludes it on that basis, regardless of the clinical result.
Why this happens on dental claims
- Newer materials and techniques, such as silver diamine fluoride for adults or laser-assisted periodontal therapy, that some plans still classify as unproven
- CDT codes for emerging services that the plan has not yet added to its covered list
- Miscoding that lands a routine service on a code the payer flags as investigational
How to appeal CO-55
- Request the plan's written definition of experimental and the specific basis for classifying this procedure that way
- Verify the coding, and submit a corrected claim if a conventional service was miscoded
- Appeal with peer-reviewed literature, professional association recognition, and regulatory clearance showing the procedure is established
- If the exclusion stands, document that the patient accepted financial responsibility and bill accordingly
How to prevent it
- Check plan policy before providing newer-technology services, and use a signed financial agreement when coverage is unclear
Related codes
How much CO-55 money is sitting in your remittances?
Drop your last 835 into the free audit. It runs in your browser, nothing uploads, and you see the answer in about a minute.