D9973 is the CDT code for bleaching applied to the outer surface of a single tooth, reported per tooth rather than per arch, typically for one tooth that has darkened after trauma or root canal treatment.
Carriers that reject every other whitening code will occasionally look at this one, because a single darkened tooth reads as a clinical problem rather than a cosmetic preference. That makes D9973 the only member of the bleaching family where a narrative, clinical photos, and the trauma history can change the outcome of a claim. The rest of the time it is a patient-pay procedure, and the billing work is charting the tooth number correctly and keeping the fee off insurance AR.
What D9973 covers
D9973 reports professional bleaching applied to the outer enamel surface of one tooth. The typical patient has a single tooth, usually an incisor, that has darkened relative to its neighbors after an injury or after root canal treatment, and wants it brought back toward the surrounding shade. The dentist isolates the tooth and applies a professional-strength peroxide agent to its facial surface, sometimes over more than one appointment.
The code is per tooth, and the tooth number belongs on the claim line. That single fact separates it from the rest of the whitening family:
- Whole-arch whitening done in the chair is D9972, per arch.
- Take-home custom trays with dispensed gel are D9975, per arch.
- Bleaching agent sealed inside the crown of a non-vital tooth is D9974, per tooth.
D9973 also does not cover microabrasion or enameloplasty to remove surface staining, composite or veneer work to mask discoloration, or any whitening of multiple teeth as a cosmetic case. A patient who wants a brighter smile is an arch-code patient. A patient with one tooth that does not match is a D9973 (or D9974) patient.
Per tooth vs per arch is the axis that gets miscoded
The bleaching codes split on two questions: where the agent is applied (outside the tooth, inside the tooth, or at home in a tray) and what the billing unit is (tooth or arch). D9973 is outside-the-tooth, per tooth. A front desk that posts “whitening” from the schedule without asking which scenario happened will most often reach for D9972 by habit, which on a single-tooth case overstates the service and puts an arch code on a claim whose narrative talks about tooth #8.
The reverse error costs money: bleaching a full arch but posting D9973 per tooth is not how the code set is built, and a claim with ten D9973 lines for a cosmetic case invites a review it will not survive. One tooth with a shade problem, D9973. An arch, D9972 or D9975.
When insurance might actually consider it
Most dental plans exclude bleaching as cosmetic across the board, and D9973 is not exempt from that language. But it is the one bleaching code where an exception argument exists, because the indication is usually a darkened tooth with a documented cause:
- Post-trauma discoloration. The tooth took a hit, the pulp was damaged, and the crown darkened over the following months. The claim argument is that the discoloration is a consequence of injury, not an elective cosmetic upgrade.
- Post-endodontic discoloration. The tooth darkened after root canal treatment. Some carriers will look at bleaching here as part of restoring the tooth’s appearance to its pre-disease state, though many of these cases route to D9974 internal bleaching instead because the stain is internal.
Whether any of this pays is plan-dependent. Treat approval as the exception, verify the plan’s cosmetic-exclusion language first, and have the patient sign a financial agreement that assumes denial. If the plan excludes all bleaching by category, no narrative overcomes the exclusion, and the honest move is to collect at time of service and skip the appeal.
Documentation that supports the claim
Whether the claim is for insurance or for the patient’s FSA/HSA paperwork, chart the same set:
- Tooth number and the shade of the treated tooth vs its neighbors, before and after.
- The cause, if known: date of trauma, date of endodontic treatment, or “unknown etiology” honestly noted.
- Material and technique: agent, concentration, isolation method, number of applications.
- Visit dates for each application in the course.
Emergency-visit crossover comes up here occasionally: a patient presents after trauma with pain, and the visit is palliative care under D9110. The bleaching conversation happens months later, once the tooth has stabilized and declared its final shade. Keep those as separate encounters in the chart; the trauma date in the D9110 note is exactly the documentation the later D9973 claim leans on.
What to get right in your PMS
- Post with the tooth number. D9973 is a tooth-level code and clearinghouses will reject or pend a line without one.
- Keep a real fee on the code. Even on patient-pay cases, the superbill needs a line-item fee for FSA/HSA submission.
- Do not let a hopeful claim sit in insurance AR. If you submit for the trauma exception, post the balance as patient responsibility from day one and treat any payment as a pleasant surprise.
- Distinguish courses from visits. If your office charges one fee per tooth for a multi-visit course, chart every visit but post the fee once, so the ledger and the chart tell the same story.
FAQs
- What is the difference between D9973 and D9972?
- The billing unit. D9973 whitens one tooth and is reported per tooth. D9972 is in-office whitening of a whole arch, reported per arch. If the dentist bleaches a single darkened lateral incisor to match its neighbors, that is D9973 x1 with the tooth number on the claim, not a D9972 arch charge.
- Does insurance ever pay for D9973?
- Occasionally, and more often than for the arch-level whitening codes. When a single tooth darkened after documented trauma or endodontic treatment, some plans will consider the bleaching restorative rather than cosmetic. Submit with the trauma or root canal history, pre-treatment photos, and a short narrative. Most plans still exclude all bleaching as cosmetic, so verify the specific plan and set patient expectations for denial.
- When should I use D9974 instead of D9973?
- By where the bleaching agent goes. D9973 applies the agent to the outside surface of the tooth. D9974 places it inside the crown of a non-vital, root-canal-treated tooth (the walking bleach technique). A dark endo-treated tooth often gets D9974 because the stain lives in the internal dentin, where external gel cannot reach it.
- Do I bill D9973 once per visit or once per tooth?
- Per tooth. Two discolored teeth treated at the same visit are two line items, each with its own tooth number. Whether repeat applications on the same tooth across multiple visits can each carry a fee is plan-dependent and worth confirming before you quote the patient; many offices charge one course fee per tooth.
Related codes
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CDT codes are maintained by the American Dental Association. This page is an editorial billing guide, not the official ADA code descriptor. Verify current coverage policies with each carrier before submitting claims.