Root canal claims require more documentation than most dental procedures — but when done correctly, they get paid. Here’s a step-by-step guide to coding, documenting, and submitting root canal claims accurately.
Before Treatment Begins: Pre-Authorization and Referrals
Before beginning root canal treatment, always review the patient’s insurance plan requirements. Key considerations:
- HMO plans — if the root canal requires an endodontist, a referral is required. Make sure the referral form is accurately completed and attach it to the claim when billing.
- Active military and Medicare plans — these plans frequently require pre-authorization for root canal treatment, especially when performed by an endodontist. Submit the required forms ahead of time to obtain approval before the appointment.
- All plans — always confirm whether pre-authorization is required when verifying benefits. If required and not obtained before treatment, the claim will be denied.
X-Ray Requirements
Root canals should never be billed without x-rays to support the treatment, and x-rays must always be periapical — never bitewing — so the entire root of the tooth is visible. At minimum, three periapical x-rays should be submitted with every root canal claim:
- Pre-treatment x-ray — must show the entire root of the tooth and the area of infection
- In-treatment x-ray — should show the treatment in progress with the cleaning file in place
- Post-treatment x-ray — must show the finished tooth with the pulp removed and filling in place
The insurance carrier may cover the claim with only the pre and post-treatment x-rays, but submitting all three gives the claim the best chance of payment.
If the canal was obstructed, an additional in-treatment x-ray is required showing the calcification of the root canal.
Clinical Narrative Requirements
A detailed narrative is essential for every root canal claim. The narrative should clearly explain why the root canal was necessary and specify the exact treatment completed. Additional narrative details are required in the following scenarios:
- Multi-visit treatment — state when treatment was started and when it was completed
- Obstructed canal — include the percentage of the root that was calcified (for example, “calcification of 30% of the length of the root”)
- Retreatment — include the date of the prior root canal treatment (at least month and year) and explain why the tooth required retreatment
- Incomplete treatment — explain why the procedure was stopped
Root canal narratives don’t need to be lengthy, but they do need to be specific.
CDT Codes for Root Canals
The most important factor when coding a root canal is the tooth’s location in the mouth. Always confirm the code matches the correct tooth type before submitting.
Initial root canal:
| Tooth Type | CDT Code |
|---|---|
| Anterior | D3310 |
| Bicuspid | D3320 |
| Molar | D3330 |
Retreatment:
| Tooth Type | CDT Code |
|---|---|
| Anterior | D3346 |
| Bicuspid | D3347 |
| Molar | D3348 |
Incomplete root canal: D3332 — use when the root canal cannot be completed. Attach a narrative explaining why the procedure was stopped and detail the revised treatment plan.
Retreatment Billing
When billing a root canal retreatment, include a doctor’s narrative and three periapical x-rays, just as with an initial root canal. In addition:
- Include the date the prior root canal was completed — most carriers require at least the month and year
- If the patient was treated at another practice, obtain the date from the patient or their previous provider
- Retreatments are subject to frequency limitations — most carriers will not cover retreatment completed within 12 months of the initial treatment
Apicoectomy Billing
When retreatment cannot resolve the issue, endodontic surgery such as an apicoectomy may be required. An apicoectomy is the surgical removal of the root tip and any surrounding infected tissue. It may be performed by a general dentist, oral surgeon, or endodontist.
CDT codes for apicoectomy:
| Tooth Type | CDT Code |
|---|---|
| Anterior | D3410 |
| Premolar (first root) | D3421 |
| Molar (first root) | D3425 |
| Each additional root | D3426 |
Key billing considerations:
- Confirm whether the patient’s plan covers apicoectomy and whether pre-authorization is required
- Some plans limit apicoectomy coverage or apply a separate lifetime maximum — verify plan-specific limitations when verifying benefits
- Submit periapical x-rays and a clinical narrative establishing medical necessity
Billing a Crown After a Root Canal
Once a root canal is completed, a restoration — often a crown — will need to be placed on the tooth. Key considerations when billing both:
Same provider vs specialist — when the root canal and crown are completed by the same provider, both can be billed on the same claim form. When the root canal is completed by a specialist, the procedures must be billed separately
Use the seat date — most insurance plans base crown payment on the seat date rather than the prep date. Do not bill the crown until after the root canal has been completed
Include all dates — note the prep date, root canal date, and seat date on the claim
Use a periapical x-ray — crowns are often billed with bitewing x-rays, but when a root canal has been done, include a periapical x-ray of the entire root showing the completed root canal treatment
Frequently Asked Questions
At least three periapical x-rays are required — pre-treatment, in-treatment, and post-treatment. X-rays must always be periapical, not bitewing, so the entire root is visible. If the canal was obstructed, a fourth x-ray showing the calcification is also required. Submitting all required x-rays gives the claim the best chance of payment.
Use D3332 for an incomplete root canal. Attach a narrative explaining why the procedure could not be completed and detail the revised treatment plan. X-rays supporting the incomplete treatment should also be included.
Yes — if both procedures were performed by the same provider, they can be billed on the same claim form. If the root canal was completed by a specialist and the crown by a general dentist, they must be billed separately. Always include the prep date, root canal date, and seat date on the claim, and use a periapical x-ray rather than bitewing x-rays when a root canal has been performed.
A root canal treats infection inside the tooth by removing the pulp, cleaning the canals, and sealing them. An apicoectomy is a surgical procedure performed when a root canal or retreatment cannot resolve the issue — it involves removing the tip of the root and surrounding infected tissue. Both require different CDT codes, different documentation, and different pre-authorization considerations.
Need Help With Root Canal Billing?
Root canal claims involve detailed documentation, specific x-ray requirements, and plan-specific rules that vary by carrier. If your team is struggling with root canal or other endodontic claims, consider partnering with eAssist. Our Success Consultants are knowledgeable about the nuances of endodontic billing and will work to get your claims submitted correctly. To learn more, schedule a free consultation.
Disclaimer: Insurance administration and dental billing recommendations presented here represent the opinions of the author or our staff and are for informational purposes only. You are responsible for your own use of the CDT Codes, insurance administration, and dental billing. For the latest CDT codes and official interpretations, contact the American Dental Association or visit ADA.org.
