The short version
# D3320 Dental Code: Premolar Endodontic Therapy
D3320 reports completed endodontic therapy on a premolar. D3310 covers anterior teeth, D3320 covers premolars, and D3330 covers molars. Canal count and treatment time don't change the tooth-type code. The code includes the clinical visits and intraoperative images needed for completion while excluding the final restoration.
- Bill D3320 when primary root canal therapy is complete on a premolar.
- Use D3310 for an anterior tooth and D3330 for a molar.
- One- or two-canal anatomy doesn't change a premolar into another tooth-type code.
- The therapy includes necessary treatment visits and intraoperative radiographs, but not the final coronal restoration.
- Delta asks for full preoperative and postoperative periapical images with a completed D3320 claim.
- In a worked claim, a $1,350 fee becomes a $950 allowable. The plan pays $760 at 80%, the patient owes $190, and the office adjusts $400.
What is D3320?
D3320 is the primary endodontic therapy code for a premolar. The procedure covers canal treatment through completion and obturation.
| Fact | D3320 |
|---|---|
| CDT category | Endodontics |
| Tooth class | Premolar |
| Reporting point | Therapy completion |
| Included | Treatment visits and intraoperative imaging |
| Public fee references | Oregon Medicaid: $526.76; Washington Medicaid: $446.12 in 2025 |
When do you bill D3320?
Use D3320 on the date the premolar root canal is completed.
- Identify the premolar tooth number.
- Document canals located, working lengths, instrumentation, irrigation, and obturation.
- Take a postoperative periapical image showing the entire root system.
- Note the coronal seal and restoration plan.
D3320 vs D3310 and D3330
Once primary therapy is complete, tooth class resolves the code.
| D3310 | D3320 | D3330 | |
|---|---|---|---|
| Tooth | Incisor or canine | Premolar | Molar |
| Canal count controls | No | No | No |
| Final restoration included | No | No | No |
| Oregon Medicaid example | $454.05 | $526.76 | $670.58 |
What does insurance actually do with D3320?
Delta requires preoperative and postoperative periapical radiographs for D3310 through D3330 claims. A cropped root or missing apex can delay adjudication. Plans can also apply an endodontic deductible, once-per-tooth limit, waiting period, or annual maximum.
- Office fee: $1,350
- Contracted allowable: $950
- Contractual adjustment: $400
- Plan payment at 80%: $760
- Patient balance: $190
Why does D3320 get denied?
- A required periapical image isn't attached.
- The image doesn't show the full root system.
- The tooth number isn't a premolar.
- The office doesn't wait for treatment completion.
- Required authorization or waiting-period conditions aren't met.
What documentation gets D3320 paid?
- Record the premolar tooth number and diagnoses.
- Attach full preoperative and postoperative periapical images.
- Document each canal treated and the obturation result.
- State the completion date.
- Note the coronal seal and planned restoration.
- Check prior endodontic history and authorization.
Common questions about D3320
Does D3320 cover both canals in a premolar?
Yes. D3320 reports the completed endodontic treatment for the premolar tooth, not one claim unit for each canal. The operative note should still identify every canal located, instrumented, disinfected, and obturated, along with the tooth number, treatment date, and completion evidence.
Is the final crown included in D3320?
No. D3320 excludes the final restoration. Report a filling, buildup, or crown only when the dentist delivers and documents that separate service. Keep the restorative procedure and date distinct from the root canal completion record so the claim shows both accurately.
Can diagnostic radiographs be billed separately?
Diagnostic images from the evaluation can be separately reported when appropriate. The AAE says intraoperative radiographs are included in therapy. Separate the evaluation images from working-length, cone-fit, and completion views in the record, and don't bill the included procedural images again.
What if treatment stops after debridement?
Don't report completed D3320. Document and report the service actually delivered under the current code that fits it, then use D3320 only if premolar therapy is later finished. The chart should make the incomplete stage, reason for stopping, and next plan clear.
Finish the premolar record with the claim
Before filing, match the premolar, completion note, and full postoperative image.
Sources
- AAE, Endodontists' Guide to CDT 2026
- AAE, Endodontists' Guide to CDT 2024
- AAE, Guide to CDT endodontic therapy
- Delta Dental, endodontic X-ray submission guide
- Georgia Medicaid, 2025 dental manual and fee material
- Washington Medicaid, July 2025 dental fee schedule
- Oregon Medicaid, June 2025 fee schedule
- AAE, dental insurance FAQ
CDT codes and nomenclature are copyright © American Dental Association. This guide explains the code in plain language; the current CDT manual is the authoritative source.
