Quick Answer: Diagnostic radiographs (D0220) and endodontic treatment (D3310) are routinely billed together. Periapical x-rays are required for endodontic diagnosis and are separately billable from the RCT code.
📋 Rule Summary
Detail | |
Code A | D0220 — Intraoral Periapical X-rays |
Code B | D3310 — Anterior Root Canal Therapy |
Same-day billing | ✅ ALLOWED |
Code A category | Diagnostic |
Code B category | Endodontic |
Documentation needed | Tooth numbers, clinical notes, and separate indications for each code |
Common mistake | Assuming that because both codes appear on the same claim they will automatically be rejected — context and documentation determine the outcome |
What Is D0220 — Intraoral Periapical X-rays?
D0220 is a CDT code in the Diagnostic category. It covers intraoral periapical x-rays services and is used when the clinical record documents the appropriate indications for this procedure.
Diagnostic codes like D0220 are billed per service rendered. They require corresponding findings in the clinical chart and, for radiographic codes, the actual images retained in the patient record.
Key documentation requirements for D0220:
Tooth number(s) clearly identified for each code (D0220 and D3310)
Clinical notes documenting the separate indications for both procedures
Date of service correctly recorded for each procedure
What Is D3310 — Anterior Root Canal Therapy?
D3310 is a CDT code in the Endodontic category. It covers anterior root canal therapy services and is used when the clinical record documents the appropriate indications for this procedure.
Endodontic codes like D3310 are billed per tooth. Radiographic evidence of the pathology and pre-op/post-op images are required for most carriers.
Key documentation requirements for D3310:
Tooth number(s) clearly identified for each code (D0220 and D3310)
Clinical notes documenting the separate indications for both procedures
Date of service correctly recorded for each procedure
D0220 and D3310 on the Same Day — The Bundling Rule Explained
Diagnostic radiographs (D0220) and endodontic treatment (D3310) are routinely billed together. Periapical x-rays are required for endodontic diagnosis and are separately billable from the RCT code.
The Exception
Most carriers allow D0220 with D3310/D3320/D3330 on the same date. Document that the x-ray was taken for diagnostic/treatment planning purposes.
What to Bill in Each Scenario
Clinical situation | Correct code(s) |
|---|---|
Both procedures performed at the same visit with documentation | Both D0220 and D3310 |
Only intraoral periapical x-rays was performed | D0220 |
Only anterior root canal therapy was performed | D3310 |
Procedures cannot be supported by chart documentation | Bill only the documented procedure |
Documentation Checklist
[ ] Tooth number(s) clearly identified for each code (D0220 and D3310)
[ ] Clinical notes documenting the separate indications for both procedures
[ ] Date of service correctly recorded for each procedure
[ ] Radiographic images retained in the patient record
[ ] Pre-operative and post-operative periapical radiographs
[ ] Narrative attached if combining uncommon code pairs on the same claim
[ ] Patient's insurance eligibility confirmed for the date of service
Billing Tips to Avoid Denial
1. Periapical x-rays are essential documentation for RCT
D0220 taken at the endodontic appointment is separately billable and strongly recommended. The pre-op, working length, and post-op x-rays all support the endo claim.
2. Bill the most comprehensive series taken
If multiple periapical images were taken, bill D0220 for the first and D0230 for each additional image. Don't bill a panoramic for endo work-up unless a full arch view was clinically necessary.
3. Include x-rays in the endo claim package
Attach radiographic images to the endo claim. Most carriers require pre-op and post-op images to approve root canal therapy — having them ready speeds reimbursement.
4. Diagnostic vs. working x-rays have the same billing code
Whether the x-ray was taken for diagnosis, working length determination, or post-op confirmation, it's billed as D0220 (periapical, single image). Bill each image taken.
Frequently Asked Questions
Can D0220 and D3310 ever be billed together?
Yes, in most cases — see the bundling rule explanation above for the conditions and any exceptions.
What is the difference between D0220 and D3310?
D0220 covers intraoral periapical x-rays services, while D3310 covers anterior root canal therapy services. They belong to different CDT categories and address different clinical procedures.
Will insurance pay for D0220 and D3310 on the same claim?
Coverage depends on the specific plan. Most carriers allow this combination with documentation. Always verify with the patient's specific plan before submitting.
What documentation is needed to bill D0220 with D3310?
At minimum: tooth numbers for each procedure, clinical notes documenting separate indications, and — for complex or unusual combinations — a brief narrative explaining why both were clinically necessary on the same date.
What happens if D0220 and D3310 are denied when billed together?
Submit an appeal with supporting documentation including the clinical chart notes, radiographs (if applicable), and a narrative explaining the separate clinical purposes. Most carriers have a formal appeal process that can reverse automatic denials.
Is it upcoding or fraud to bill D0220 and D3310 on the same day?
Billing two codes that represent genuinely distinct, separately documented services is not fraud — it is accurate coding. Fraud occurs when a code is billed for a service that was not performed. Ensure your chart documentation fully supports each code submitted.