CDT 2027 and ICD-10-CM: clean up your claim crosswalk
Use the mismatch between ICD-10-CM and CDT effective dates to fix diagnosis pointers, payer rules and medical-dental claim workflows before January denials appear.
The three code types
| Code | What it tells you | Example use |
|---|---|---|
| Group code | CO contractual obligation, PR patient responsibility, OA other adjustment | CO amounts are generally not billable to the patient for in-network care |
| CARC | The reason for the adjustment | Frequency limitation reached, missing information, non-covered |
| RARC | Additional explanation | Which document was missing, or which policy applied |
A triage workflow
- SortCorrectable (data/coding errors), appealable (necessity, frequency exception, downgrade), or non-covered.
- Fix fastCorrect and resubmit data errors within days to protect timely filing.
- Appeal with evidenceNarrative, radiographs, charting and plan language.
- Close the loopLog the root cause and fix the upstream step.
Track the right metrics
- Initial denial rate by claim count and by dollars
- Denial reason Pareto (top causes by dollars)
- Appeal overturn rate and cycle time
- Denials prevented month over month
How Dental Billing Community helps
We work denials within 48 hours of the ERA, appeal with complete documentation and report root causes monthly so the same denial stops coming back.
Frequently asked questions
Can we bill the patient for a CO adjustment?
Generally no for in-network care — CO indicates a contractual obligation. Check your contract and state rules.
Where are the official code lists?
X12 publishes the CARC and RARC lists and updates them regularly.
Sources & further reading
Educational content only — not legal, coding-certification or payer-specific advice. Code sets (CDT, CPT, ICD-10-CM, HCPCS) and payer policies change; always confirm against the current code manual and the patient's plan. CDT is © American Dental Association. CPT is © American Medical Association.