D3330Endodontic Therapy, Molar Tooth (Excluding Final Restoration)

What This Code Covers

D3330 is the CDT code for a complete root canal on a molar tooth. Molars are the most complex teeth to treat endodontically because they typically have three to four canals spread across two or three roots. The procedure involves removing all pulp tissue from every canal, cleaning and shaping each one, and filling them with obturation material. Because of the added complexity and chair time, D3330 carries the highest reimbursement of the three primary root canal codes. A crown is almost always required afterward, but the final restoration is billed separately.

Billing Guide

Bill this code when:

• The dentist completes a root canal on a permanent molar tooth (teeth 1-3, 14-16, 17-19, 30-32)
• All canals have been located, instrumented, and obturated
• The procedure is fully finished, whether completed in one visit or across multiple appointments
• The tooth is a permanent molar, not a primary (baby) molar

Do not bill this code when:

• The tooth is an anterior or premolar, so use D3310 or D3320 respectively
• The root canal was started but not completed, so bill D3331 (incomplete endodontic therapy)
• You are retreating a failed root canal on a molar, which requires D3348
• Only a pulpotomy was performed (partial pulp removal), which uses D3220 or D3222

Insurance and Denial Prevention

Key Payer Rules:

• Most PPO plans cover D3330 at 80% under major services after the deductible, though some plans place it at 50%
• Molar root canals are the most frequently preauthorized endodontic procedure. Always check the payer's preauth requirements before starting treatment
• Some plans have a combined frequency limit on endodontic procedures per benefit year, so if the patient already had a root canal that year, verify remaining benefits
• Medicaid programs in many states do not cover molar root canals for adults. Check the state's covered procedure list before beginning treatment

Common Denials and How to Respond:

• Tooth not restorable or questionable prognosis --> Submit a detailed narrative with clinical photographs, the periapical radiograph, and a description of the planned restoration. Explain the bone support, remaining tooth structure, and why the tooth is worth saving.
• Downcoded to D3320 (premolar) --> Confirm the tooth number is correctly recorded. Include a radiograph that clearly shows molar anatomy with multiple roots. Appeal with the corrected tooth number and ADA tooth chart if the payer misclassified the tooth.
• Exceeds plan maximum or annual limit reached --> Inform the patient about their remaining benefit balance. If the root canal is urgent, proceed and have the patient pay the difference. Submit the claim so it applies toward next year's maximum if the plan allows rollover.