D3348 is the CDT code for the retreatment of previous root canal therapy on a molar tooth — redoing a failed or failing root canal on a back tooth. It covers removing the prior root canal filling, re-cleaning and re-shaping the canals, and re-obturating them, excluding the final restoration, which is reported separately.
Informational only — confirm the official CDT descriptor and your payers' rules independently. This is general guidance, not billing, coding, or clinical advice.
When to Use the D3348 Code
Report D3348 when a dentist re-treats a molar that has had a prior root canal — typically because of persistent or recurrent infection, a missed canal, a failed obturation, or new decay compromising the seal — and the tooth is being saved rather than extracted.
The distinguishing factor is the prior treatment. An initial root canal on a molar is D3330 (endodontic therapy, molar), not D3348; use the retreatment code only when there's a documented previous root canal. Match the tooth type as well: D3346 is retreatment of an anterior tooth and D3347 is retreatment of a premolar. Because molars have more canals, retreatment is the most complex of the three and is often referred to an endodontist.
Documentation & Clinical Scenarios
Retreatment claims hinge on showing the prior treatment and the reason for redoing it:
- Tooth number and documentation that a previous root canal exists on that tooth.
- The reason for retreatment — persistent symptoms, periapical radiolucency, a missed or under-filled canal, or a failed seal.
- Pre-operative radiograph(s) showing the existing fill and the failure, often with a post-op film.
- Procedure detail — removal of the prior filling material, re-cleaning, and re-obturation across the molar's canals.
Because the final restoration is excluded, any new crown or buildup is documented and billed under its own code, and a narrative is often expected to justify the redo.
Insurance & Billing Tips
- Verify benefits and history. Confirm endodontic retreatment coverage and any waiting period; some plans limit how soon a molar can be re-treated after the original therapy.
- Document the prior treatment. A retreatment claim should show the tooth was previously root-canaled; without it, the payer may question the code.
- Use the right code. D3348 is for molar retreatment only — D3346 (anterior) and D3347 (premolar) apply to other teeth; an initial molar canal is D3330.
- Bill the restoration separately. Any new crown or buildup is its own line, never bundled into D3348.
- Expect to appeal. Molar retreatments are higher-cost and reviewed closely; a narrative plus the pre-op radiograph showing the failure supports the claim.
Example Case
A 52-year-old established patient calls because a lower back tooth that was root-canaled years ago is throbbing again. A periapical radiograph of tooth #19 (a molar) shows a periapical lesion and an under-filled canal. The dentist removes the old filling material, re-cleans and re-fills the canals, and documents the failure and the redo — reported as D3348. The tooth is later restored under its own code. Because the office documented the prior root canal and the reason for retreatment and attached the radiograph, the claim is supported through review.
On the phone, patients don't say "D3348" — they say a treated molar is killing them again. DentalReception AI answers those calls in under two rings, 24/7, captures the symptom and history in the patient's words, and books the visit live into your schedule — while every clinical and coverage decision routes to your team. See how it handles root canal calls, or book a demo.
Frequently Asked Questions
What's the difference between D3348 and D3330?
D3348 is the retreatment of a molar that already had a root canal, while D3330 is the initial endodontic therapy on a molar. The retreatment code applies only when there's a documented previous root canal being redone. Billing D3330 for a redo — or D3348 for a first-time molar canal — is a common error that can trigger a denial, so confirm the tooth's endodontic history before coding.
How is D3348 different from D3346 and D3347?
All three are endodontic retreatment codes; the difference is the tooth. D3346 is for anterior (front) teeth, D3347 for premolars, and D3348 for molars. Molars have the most canals, so molar retreatment is the most complex of the three and is frequently referred to an endodontist. Each tooth type is reported separately, and using the wrong retreatment code can cause a denial or down-code.
Does D3348 include the new crown or restoration?
No. D3348 covers the endodontic retreatment of the molar only and excludes the final restoration. Any new crown, buildup, or filling placed after the retreatment is reported separately under its own CDT code. Billing the restoration on the same line as the retreatment is a common cause of bundling denials, so it should always be reported on its own line.
Does D3348 require a pre-authorization?
Molar retreatment is a higher-cost procedure reviewed closely by payers, so a pre-treatment estimate is often recommended even when a formal pre-authorization isn't required. Confirming retreatment coverage and any waiting period, and documenting the prior root canal with a radiograph showing the failure, both reduces the chance of a denial and provides the basis for an appeal if the claim is questioned.
Confirm the current CDT descriptor and your specific payer policies before billing — browse the full dental code library or see our insurance verification feature.