D1355 Dental Code: What It Covers and How to Bill It

This code covers one of the narrower procedures in the CDT code set, and payers are picky about how it gets documented. Get the chart note and the coverage check right before the visit, and the claim has a real chance of paying the first time.

D1355 is the CDT code for caries preventive medicament application, per tooth. It covers a medicament placed on a single tooth to stop new decay or help remineralize an early lesion before a cavity forms. The code's descriptor excludes topical fluoride treatments, which are billed under separate codes. Dentists and hygienists report D1355 when they place silver diamine fluoride, silver nitrate, or another non-fluoride preventive medicament on a tooth with early signs of decay or high caries risk, before any restoration is needed.

D1355 is billed once per tooth treated, so three teeth need three units, not one. Coverage is inconsistent: some dental plans pay D1355 as a preventive benefit, some apply it to basic services with a copay, and some plans do not cover it at all. Medical plans may treat the same medicament differently. Check the plan's coverage, frequency limit, and age limit for D1355 before the visit, not after the claim comes back denied.

D1354 and D1355 both sometimes apply to the same product, usually silver diamine fluoride, but they describe different situations. D1354 is the interim caries arresting medicament application. It gets billed when the tooth already has active, cavitated decay, and the medicament is placed to stop that decay from getting worse, often because the patient can't yet have a filling or extraction. D1355 is the caries preventive medicament application. It gets billed when there is no cavity yet and the medicament goes on sound or early-lesion enamel to keep decay from starting.

The chart note should state which situation applies: active, cavitated lesion for D1354, or prevention and remineralization with no cavity for D1355. Billing D1355 for a tooth that already has an open cavity is a common reason claims come back downcoded or denied, because the documentation does not match what the code describes.

Before the claim goes out, the chart note should include the tooth number, the medicament used, and why the tooth qualifies: high caries risk or an early white-spot lesion, not an open cavity. Some payers ask for a short narrative with this code since it moves less volume than a restorative code. If you're not sure how a payer categorizes D1355, the CDT code set lists the current descriptor so your claim uses the exact wording the payer expects.

In many states a hygienist can place the medicament for D1355 under general or direct supervision, but scope of practice rules vary by state dental board. The provider entered on the claim should match the person who actually placed the medicament, charted under their own provider ID if the state requires that split, not automatically the supervising dentist.

Most plans that pay D1355 cap how many times they'll pay for it on the same tooth in a year, often once or twice. If a plan allows D1355 twice a year per tooth and the practice treats four teeth at one visit, that visit bills four units of D1355, and those same four teeth could use up to eight units for the year if every tooth gets a second application later. Plug in your own patient's plan limit and tooth count before you submit a claim with more units than the plan allows.

Coverage for the D1355 dental code is not standard across dental plans. Some pay it in full as a preventive benefit, some put it under basic services with a deductible and copay, and some plans won't pay for it at all, no matter how the chart is documented. We see practices get caught off guard by this because the code's description never changes, but the plan's category for it does.

The only way to know before the visit is to check that specific patient's plan. That's what insurance verification is for: the front desk signs in, runs a check in one click, and sees the plan's preventive and basic benefit split before the patient sits down in the chair. The office still decides which CDT code to bill. The software shows what the plan says about the code, it doesn't pick the code.

If a claim for D1355 comes back denied, check three things first: was the tooth number correct, does the chart note describe prevention rather than an active cavity, and does the plan cover this code at all. If the plan requires predetermination for preventive medicaments, run that before the visit, not after. Our guide on dental predetermination walks through the steps most plans use. If the denial points to the claim form itself, a missing tooth number or a wrong place-of-service field is the usual cause. Our guide to the ADA dental claim form walks through each box.

If your team is still calling payers one by one to find out whether D1355 is covered before every medicament visit, you can book time to see how insurance verification works for your office.

What is the D1354 dental code?

D1354 is the CDT code for interim caries arresting medicament application, per tooth. It's billed when a medicament, most often silver diamine fluoride, is placed on a tooth with an active, cavitated lesion to arrest the decay, usually because the patient can't yet have a filling or extraction. D1354 treats an existing cavity, while D1355 prevents one from forming.

D1355 vs. D1354: which code do I bill?

Bill D1354 when the tooth already has an active cavity and the medicament is meant to stop it from getting worse. Bill D1355 when there's no cavity yet and the medicament is meant to prevent one or remineralize an early lesion. The chart note should state which situation applies before the claim goes out, since the two codes describe different clinical pictures.

What is the D2991 dental code?

D2991 is a newer CDT code, added in 2024, for a procedure related to caries management that's separate from both D1354 and D1355. Payers are still settling how they categorize and price D2991, so check the current CDT descriptor and the specific plan's fee schedule before you bill it. Don't assume it pays the same way D1355 does.

Is there a dental code for caries excavation?

There's no separate CDT code just for removing decay. Excavating a cavity is part of the restorative procedure, so it's billed under the matching filling code, such as D2140 for a one-surface amalgam restoration, not as its own line item. If a provider uses a by-report code for an unusual situation, that typically falls under the D1999 dental code, the unspecified preventive procedure by report code, not a dedicated excavation code.