D3348 is the CDT code for endodontic retreatment of a previously treated molar tooth. It applies when a prior root canal on a molar has failed and requires removal of the existing filling material, re-instrumentation, and re-obturation of all canals. Molar retreatment is technically more demanding than anterior retreatment due to the number of canals and complex root anatomy, and it receives greater payer scrutiny as a result.
Last updated June 2026 ยท Reviewed by the PracticeAlpha billing team
Get help with D3348 claims →Radiographic evidence of a persistent or enlarging periapical lesion on a previously root-canal-treated molar. The lesion indicates incomplete debridement or reinfection of one or more canals from the original treatment.
CBCT or periapical radiograph reveals an untreated canal in a molar that had prior root canal therapy. Missed canals (such as the MB2 in upper molars) are a common cause of molar endodontic failure and a clear indication for retreatment.
Prior root canal fill is radiographically short, has voids, or the coronal seal has been compromised allowing bacterial recontamination. Retreatment is indicated when the original obturation quality cannot support long-term success of the restoration.
The most common molar retreatment coding error. D3330 is for initial root canal therapy on a molar that has never been treated. D3348 is for retreatment of a previously treated molar. If claim history shows prior RCT on that tooth and you bill D3330, payers will deny the claim or flag it for audit. Cross-check the patient's dental history and radiographic record before selecting the code.
Retreatment requires clinical evidence that the prior root canal failed. The pre-operative periapical radiograph must show the existing root canal obturation and ideally a periapical lesion, short fill, voids, or missed canal. A clinical note documenting signs and symptoms such as pain, swelling, or sinus tract is essential. Submitting a claim without this documentation invites a denial for lack of medical necessity.
Molar retreatment is a high-cost procedure and payers routinely require pre-auth. Submit pre-auth with the pre-operative radiograph and a written narrative before scheduling treatment. For complex cases involving CBCT imaging or specialist referral, include that documentation as well. Proceeding without pre-auth approval is one of the most preventable denial reasons for D3348.
For molar teeth, payers frequently question whether retreatment is the appropriate treatment versus extraction followed by an implant. A narrative explaining restorability, periodontal status, strategic value, patient preference, and clinical prognosis strengthens the claim considerably. Without it, retreatment on a molar may be denied as not medically necessary.
Some plans exclude retreatment altogether or impose waiting periods after initial endodontic treatment. Always verify the patient's specific plan benefits before scheduling. If the plan covers retreatment, confirm whether referral to an endodontist affects coverage, as some plans have different fee schedules for specialist versus general dentist retreatment.
Must clearly show the existing root canal fill in all roots and ideally periapical pathology, short obturation, voids, or evidence of a missed canal. This is the cornerstone of the pre-authorization submission and claim documentation.
Specific signs and symptoms such as persistent pain, swelling, sinus tract on the attached gingiva, sensitivity to percussion or palpation, or new periapical pathology on a tooth with prior RCT. Be precise about what has changed since the original treatment.
Explain why retreatment was chosen over extraction, addressing restorability (adequate tooth structure remaining), periodontal health, strategic importance of the molar, and the realistic prognosis of retreatment. This narrative is especially important for molar cases where extraction plus implant is a common payer alternative.
Records or radiographs from the original root canal help document the history and support the retreatment decision. If the prior treatment was performed at another practice, note whether records were requested and include them when obtainable.
Confirming completed obturation of all canals after retreatment. The post-op x-ray documents the quality of the retreatment including canal length, taper, and density of the fill. Many payers require this to finalize reimbursement on molar endodontic procedures.
Record the pre-auth approval number in the patient record and include it on the claim form. If you did not obtain pre-auth for a plan that requires it, expect a denial. Retroactive pre-auth requests are rarely granted for elective retreatment.
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Get a free AR analysisD3348 is the CDT code for endodontic retreatment of a previously treated molar tooth. It covers removal of existing root canal filling material, re-instrumentation, and re-obturation of the canal system in a molar when the original root canal therapy has failed. Molars typically have three or more canals, making retreatment more technically complex than anterior cases.
D3330 is initial root canal therapy on a molar that has never been endodontically treated. D3348 is retreatment of a molar that already had a root canal. If the tooth has prior RCT, the correct code is D3348. Billing D3330 for a retreatment case is a coding error that triggers denials and audit exposure.
D3346 is endodontic retreatment for anterior teeth (incisors and canines). D3348 is endodontic retreatment for molar teeth. Premolar retreatment uses D3347. The tooth position determines the code. Confirm the tooth number before selecting the retreatment code.
Common reasons include billing D3330 instead of D3348, insufficient documentation of endodontic failure, missing pre-authorization, no written narrative justifying retreatment over extraction, plan-specific retreatment exclusions, and frequency limitations. Molar retreatment claims receive closer payer scrutiny than anterior retreatment due to higher associated fees.
Many dental plans require pre-authorization for molar endodontic retreatment. Submit pre-auth with the pre-operative radiograph and a written narrative before scheduling. Check the patient's specific plan requirements before treatment. Molar retreatment is a high-cost procedure and payers routinely review these claims before approval.
Required documentation includes a pre-operative periapical radiograph showing the existing root canal obturation and periapical status, clinical notes documenting signs of endodontic failure, a narrative justifying retreatment over extraction, prior treatment records when available, and a post-operative radiograph confirming completed obturation of all canals. For complex anatomy cases, CBCT imaging can strengthen the claim.
D3348 and a crown restoration are separate procedures with separate CDT codes and can be billed together if performed on the same appointment. However, confirm the patient's plan does not bundle the buildup or temporary restoration into the retreatment fee. Scheduling them at separate appointments is common practice and simplifies claim submission.
Search all CDT codes in our dental coding guide.