Night Guard Repair Dental Code (D9942): Billing Guide

What D9942 covers

D9942 reports restoring an occlusal guard the patient already owns. The appliance came back broken, cracked, worn through at a contact, or no longer seating on an arch that has changed since it was made, and the office puts it back into service rather than starting over.

The code joins repair and reline with an and/or, which has three consequences:

• Both halves go on one line. A visit that rebuilds a fractured section and resurfaces the fitting surface is one D9942. There is no separate guard reline code.
• Nothing in the code counts. Not fractures, surfaces, or lab time. Two cracks in the same appliance on the same day is one procedure.
• It carries no per-appliance qualifier. D9936, the cleaning and inspection code added for CDT 2026, has one; D9942 does not. If a patient’s upper and lower guards were both restored, ask the plan how it wants that reported rather than assuming two lines will pay. Put arch identification on the claim either way; PEHP requires it on D9942.

The custom sleep apnea appliance family is laid out the same way, which makes it easy to confuse. It separates adjustment (D9948) from repair (D9949) just as the guard family separates D9943 from D9942, but its repair code includes no reline and its appliance sits under a different benefit, often a medical one. Match the code to the appliance on file, not to the work the dentist did.

Repair it or remake it

A remake typically costs several times what a repair does, and two plan clocks decide which one pays.

The replacement clock is long. Plans that cover guards limit how often. Centene’s occlusal guard policy allows one per member per 36 months. PEHP allows one per arch in a seven-year period. A patient who cracked a guard eighteen months into a 36-month interval has no covered remake, which is the situation D9942 exists for.

The repair clock is separate and can be tighter. Where a plan covers the repair at all, it tends to limit it twice. PEHP bundles repairs and adjustments within six months of delivery into the original appliance fee, then allows one repair for the life of the appliance, and only if PEHP paid for the guard. Once that allowance is used, the appliance has no repair benefit left, whatever the replacement clock says.

On a plan with a long guard interval, then, the repair may be the only guard line the carrier will consider for years. All of this is plan-dependent and should not be quoted from memory.

Where D9942 sits against the rest of the family

Four things can happen to a guard after delivery, each with its own code. What decides the code is what the appliance needed, not how long the appointment took.

• It fits but rubs. Relieving the sore spot or refining the contacts on an intact guard is D9943.
• It broke, or it stopped fitting. Rebuilding the fracture, adding material, or processing a new fitting surface is D9942.
• It is dirty but sound. Cleaning and inspecting an existing guard with no change to the fit is D9936, new for CDT 2026 and counted per appliance.
• It is finished. A guard worn through, distorted beyond repair, or made for a dentition that no longer exists is remade under D9944, D9945, or D9946 depending on material and span.

Keep D9936 off the repair claim. Delta Dental Insurance Company’s 2026 code summary states that on plans covering the cleaning code, it is not billable to the patient or to Delta when performed with D9942. A guard that comes in for repair gets cleaned as part of the process, and adding the cleaning line can be a contract problem, not just a rejected line.

Confirm the appliance family first. Occlusal guards protect the dentition from grinding and clenching. UnitedHealthcare’s occlusal guard policy, effective January 1 2026, lists D9942 among its codes and states that guards are not indicated for temporomandibular disorders, headaches or craniofacial pain, orthodontic tooth movement, or sport, routing TMD appliances to its medical TMJ policy. That boundary follows the appliance into its repair: if the original was fabricated as a TMD orthotic under D7880, the repair belongs to that policy and that insurer, not to D9942.

The retired D9940 was the by-report occlusal guard code, deleted in the CDT 2019 update and replaced by the three material-and-span codes. Offices still carrying it in the fee schedule usually have a stale guard maintenance setup as well.

Coverage, and what the repair inherits

Guard codes are widely excluded as cosmetic or non-essential; the D9944 page covers that exclusion and the predetermination that answers it. The repair inherits more than the exclusion.

Benefit status. If the plan does not cover the guard, it almost certainly does not cover restoring it. CareFirst’s comprehensive dental reference lists D9942 as typically not covered, depending on the individual contract, the same language it applies to the guard codes.

Payment history. Because PEHP allows the repair only when it paid for the original device, a patient whose guard came from a previous employer’s plan, or who paid out of pocket, may have no repair benefit even on a contract that carries the code. This is not universal, but it is worth asking on any repair claim.

Delivery date. PEHP’s six-month post-delivery bundling names D9942 explicitly. CareFirst applies its six-month window to the adjustment code and states none for the repair. Two published policies with different shapes are the reason not to assume either.

Which appliance. Some plans exclude specific guards rather than the category. PEHP covers D9944 and D9945 and marks the partial-arch D9946 not covered, so whether a repair is inside the benefit depends on which appliance the patient has.

Medical crossover works the same way the D9944 page describes for the appliance. It is sometimes available where a documented TMD diagnosis drives the case, it runs on a plan-designated medical CPT code and an ICD-10 diagnosis rather than the CDT code, and most general offices do not run the workflow because the volume does not justify it. A repair is a smaller fee than the appliance, so the case for it is weaker still. If the appliance was fabricated to treat a TMD, it belonged to that route from the start, and the repair follows it.

Documentation that shows a repair, not a remake

The carrier is checking that an appliance the patient already had came back and left again. The record should make that unambiguous.

• The original delivery date and the code the appliance went out under. This is the most important field on the claim. It shows the appliance exists, answers any post-delivery bundling window, and on a plan like PEHP confirms the carrier paid for the guard. PEHP asks for the delivery date or the most recent repair date on the claim.
• The appliance’s history since delivery. Prior adjustments and repairs, with dates. Where the benefit is one per life of the appliance, this is what the carrier counts, and it tells you in advance whether any benefit remains.
• What was wrong with it, in one specific sentence: fractured at the left posterior, worn through at the canine, no longer seating after tooth #30 was crowned.
• What was done to restore it. That material was added or a new fitting surface was processed, and the appliance was returned to the patient. Avoid any wording that reads as a new appliance.
• Arch identification. The code does not carry it, published guard policies require it, and frequency limits are commonly written per arch.
• The narrative supporting the original diagnosis. PEHP asks for a narrative on the repair claim confirming the severe sleep bruxism diagnosis, not just a description of the breakage.

Practice software setup

The usual failure on this code is that it is not set up, so the visit gets written off or billed as a new guard, and both are wrong.

1. Confirm D9942 is in the active procedure list with a fee, not sitting inactive from an old code-set import. Label it by what it does, such as “Occlusal guard repair or reline,” so it is not confused with the other guard codes.
2. Show the guard’s delivery date and payment source on the account, since both decide whether the claim pays.
3. Track prior repairs per appliance, not per patient. A once-per-life-of-the-appliance benefit counts against a specific guard, and a patient-level count gives the wrong answer when the patient has had two appliances.
4. Do not let a repair post as a new guard. A remake billed on D9944 through D9946 inside the replacement window is a frequency denial and a much larger patient balance. If your system can warn on the guard codes when a prior guard is on file, turn that on.

For how the arch, the delivery date, and the remarks field are filled in on the claim, see the ADA dental claim form guide.