D3320 Dental Code: What It Covers and How to Bill It

The D3320 dental code stands for endodontic therapy, premolar tooth, excluding the final restoration. It is a CDT code used to bill a root canal performed on one of the eight premolar teeth, the teeth located between the canines and the molars. The code covers the full root canal procedure: opening the tooth, removing the infected or damaged pulp, cleaning and shaping the canals, and filling them with a sealing material.

D3320 does not include the crown or filling placed afterward to restore the tooth; that step gets billed under a separate restorative code. Premolars can have one, two, or even three canals, so the fee tied to D3320 usually runs higher than D3310 (anterior teeth, usually one canal) and lower than D3330 (molars, often three or four canals). Most dental plans pay for D3320 once per tooth, not once per visit, and many apply it toward the plan's yearly maximum.

The D3320 dental code sits in the middle of the root canal family of CDT codes. D3310 covers the six front teeth, the incisors and canines, which usually have a single canal and take less chair time. D3330 covers the molars in the back of the mouth, which often have three or four canals and take the longest. D3320 sits between the two, for the eight premolars, which often have one or two canals and sometimes three on the upper first premolar.

The fee schedule usually tracks that same order. If a plan pays $650 for D3310, $780 for D3320, and $980 for D3330, that is a $130 jump from anterior to premolar and a $200 jump from premolar to molar. Plug in your own fee schedule to see the gap on your own plans.

We've broken down the same kind of coverage and billing detail for other CDT codes, including the D5110 dental code for a complete denture and the D2160 dental code for a filling. The pattern repeats across all of them: one code for the procedure, a separate code for anything added on afterward, and a frequency limit buried somewhere in the plan document.

D3320 pays for the root canal itself, not for what comes after it. A few things a front desk should flag before the visit so the patient isn't surprised at checkout:

• The permanent crown or filling placed over the treated tooth. That's a separate restorative code, billed and paid on its own.
• A post and core, if the tooth needs one to hold a crown in place.
• Retreatment, if a prior root canal on the same tooth fails. That falls under a different code (D3346 through D3348) and often needs a narrative explaining why.
• An extraction, if the tooth can't be saved. Whether a tooth is restorable or should come out is a clinical decision for the treating provider, not a billing question.

If you need the exact current wording for D3320 or a related code, our CDT procedure code guide lists the description for each one.

Here's what we see at practices: a patient is scheduled for a root canal on a premolar, and nobody checks the plan until the day of the appointment. The front desk finds out then that endodontics pays at a lower percentage, or that there's a waiting period, or that the patient already used their frequency limit on that tooth. By then the patient is in the chair and the number on the chart doesn't match what checkout tells them.

That gap is what insurance verification closes. The front desk signs in and runs a check in one click before the visit. The check comes back with the plan's annual maximum, what's left of it, and whether a code like D3320 is covered, and at what percentage. Plans start from $49 a month per location plus $2.50 or less per check we find, priced by how many checks your office runs each month, so a practice running fifty checks pays a different rate than one running a thousand.

According to the ADA Health Policy Institute's 2026 survey, 43.3% of dentists already use AI for at least one task in the practice, and insurance verification is the number two planned use, at 32.6% planned against 13.6% doing it today. That gap between planned and current matches what we hear on the phone: practices want this step covered, the front desk just hasn't had the hours to set it up between patients.

If you want to see whether a payer is already set up for a one click check, we keep a searchable list of every payer we verify in real time.

A few patterns come up again and again on premolar root canal claims:

• Wrong tooth number on the claim. Premolars are numbered 4, 5, 12, 13, 20, 21, 28, and 29; a transposed digit is an easy denial.
• Missing pre-op or post-op x-ray showing the filled canals.
• Frequency limit already used on that tooth, sometimes from treatment at a prior office.
• Patient not eligible on the date of service, usually because coverage lapsed or changed and nobody rechecked it.
• Coordination of benefits not sorted out when the patient has two plans.

Running an eligibility check before the visit catches most of these upfront. For the full list of what an insurance check actually confirms, see our guide on what dental insurance verification actually takes. If you want to see how a one click check would fit your schedule, you can book a short call with our team.

What does dental code D3320 mean?

D3320 means endodontic therapy, premolar tooth, excluding the final restoration. It's the CDT code used to bill the root canal procedure itself, the cleaning and filling of the canals, on any of the eight premolar teeth.

Is D3330 a root canal?

Yes. D3330 is endodontic therapy, molar tooth, excluding the final restoration. It covers the same root canal procedure as D3310 and D3320, just on a molar instead of a front tooth or premolar.

Is pulpotomy the same as root canal?

No. A pulpotomy removes only the pulp in the crown of the tooth and is billed under a different code, often as an emergency step or on a primary tooth. A full root canal, billed under D3310, D3320, or D3330, removes the pulp from the entire canal system down to the root tip. Whether a tooth needs a pulpotomy or a full root canal is a clinical decision for the treating provider.

Does insurance pay for D1330?

D1330 is oral hygiene instructions, not a root canal code, so it isn't related to D3320. Coverage varies by plan: some pay it as a small preventive benefit and some don't cover it separately at all. Check the specific plan to see how it's handled.