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 the repair and the reline with an and/or, and that small piece of punctuation is doing real work.

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

The custom sleep apnea appliance family is laid out the same way and that is the trap. It separates the adjustment (D9948) from the repair (D9949) exactly as the guard family separates D9943 from D9942, but its repair code carries 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

This is the decision the visit actually turns on, and a remake typically runs several times what the repair does. It is worth walking through in that order rather than reaching for the guard code out of habit.

The replacement clock is long. Plans that cover guards do not cover them 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 thirty-six-month interval has no covered remake available, which is exactly the situation D9942 exists for.

The repair clock is separate and can be shorter than you expect. Where a plan carries the repair at all, it tends to gate it twice. PEHP does not open the benefit until six months after delivery, allows it once for the life of the appliance, and conditions it on PEHP having paid for the guard in the first place. Once that single allowance is used, the appliance has no repair benefit left regardless of what the replacement clock says.

A repair inside the replacement window is sometimes the only payable line. That is the useful version of the point. It is not that repairs pay well, it is that on a plan with a long guard interval the repair may be the only occlusal-guard line the carrier will still consider for years. All of it is plan-dependent and none of it should be quoted from memory.

Where D9942 sits against the rest of the family

Four things can happen to a guard after delivery and each has its own code. The axis running through them is what the appliance needed, not how long the appointment took.

• It fits but rubs. Relieve the sore spot, refine the contacts, and the guard leaves intact. That is D9943.
• It broke, or it stopped fitting. Rebuild the fracture, add material back, process a new fitting surface. That is D9942.
• It is dirty but sound. Cleaning and inspecting an existing guard with nothing about the fit altered is D9936, new for CDT 2026 and counted per appliance.
• It is finished. A guard worn through, distorted beyond restoring, or made for a dentition that no longer exists gets remade under D9944, D9945, or D9946 depending on material and span.

The one pairing to watch is D9936 alongside D9942. 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 in conjunction with D9942. A guard that comes back for a repair gets cleaned as part of the process, and adding the cleaning line to that claim can be a contract problem rather than just a rejected line.

The appliance family question comes first, before any of this. Occlusal guards protect the dentition from grinding and clenching. UnitedHealthcare’s occlusal guard policy, effective January 1 2026, lists D9942 among the codes the policy applies to, and the same policy states that guards are not indicated for treating temporomandibular disorders, headaches or craniofacial pain, orthodontic tooth movement, or sport, routing TMD appliances to its medical TMJ policy instead. 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 is worth a glance while you are in the fee schedule. It 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 usually have a stale maintenance setup alongside it.

Coverage, and what the repair inherits

The guard codes themselves are widely excluded as cosmetic or non-essential, and the D9944 page covers that exclusion and the predetermination habit that answers it. What is specific to the repair is that it inherits more than the exclusion.

It inherits the appliance’s 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, with the answer depending on the individual contract, which is the same language it applies to the guard codes themselves.

It can inherit the appliance’s payment history. PEHP allows the repair only when PEHP paid for the original device. A patient who arrived with a guard from a previous employer’s plan, or who paid out of pocket for it, may have no repair benefit even on a contract that carries the code. This is not a universal rule, but it is a question worth asking on any repair claim.

It can inherit the delivery date. PEHP’s post-delivery bundling covers D9942 explicitly: adjustments and repairs performed within six months of delivery are part of the original appliance fee and are not separately reimbursed. CareFirst applies its six-month window to the adjustment code and does not state one for the repair. Two published policies, two different shapes, which is the argument against assuming either.

The category exclusion is not always the whole category. PEHP covers D9944 and D9945 and marks the partial-arch D9946 not covered. On a plan built that way, whether the repair is inside or outside the benefit depends on which appliance the patient has.

On medical crossover, the honest answer is the same one the D9944 page gives for the appliance: it is sometimes available where a documented TMD diagnosis drives the case, it runs on a medical CPT code and an ICD-10 diagnosis rather than the CDT code, and the specific code is plan-designated rather than standard. Most general offices do not run the workflow because the volume does not justify it. A repair is a smaller fee than the appliance was, so the calculation is even less favorable. If the appliance was genuinely fabricated to treat a TMD, the appliance belonged to that route from the beginning, and the repair follows it there.

Documentation that shows a repair, not a remake

A carrier reading a D9942 claim is checking one thing: 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 single most load-bearing field on the claim. It establishes that the appliance exists, it answers any post-delivery bundling window, and on a plan like PEHP it is how the carrier confirms it 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 prior repairs, with dates. Where the benefit is capped at one for the life of the appliance, this is what the carrier counts against, and it is also what tells you in advance whether the visit has anything left to pay.
• What was wrong with it. Fractured at the left posterior, worn through at the canine, no longer seating after tooth #30 was crowned. Specific, in one sentence.
• What was done to restore it. That material was added or a new fitting surface was processed, and that the appliance returned to the patient. The word to avoid is any phrasing that reads as a new appliance, because that is the audit question.
• 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. The repair claim can be asked to re-establish why the appliance existed at all.

What to get right in your PMS

The menus differ across Open Dental, Dentrix, Eaglesoft, Curve, and Carestream, but the failure here is not a systems problem, it is that the code is not in the list and nobody notices.

1. Confirm D9942 is actually in the active procedure list with a fee on it. This is the whole problem in one line. An office without the code set up has two options at the chair, write the visit off or bill a new guard, and both are wrong. Add it, price it, and make sure it is not sitting inactive from a code-set import years ago.
2. Name it by what it does. Something like “Occlusal guard repair or reline” rather than a generic guard label. Every code in this family reads as some variant of “occlusal guard” by default, which is how they get grabbed interchangeably.
3. Surface the guard’s delivery date and payment source on the account. Both decide whether this claim pays, and whoever posts the repair needs them without hunting through the ledger.
4. Track prior repairs on the appliance, not just on the patient. A once-per-life-of-the-appliance benefit is counted against a specific guard. If the patient has been through two appliances, a patient-level count gives the wrong answer.
5. Do not let a repair post as a new guard. A remake billed on D9944 through D9946 inside the plan’s replacement window is a frequency denial and a much larger patient balance than a repair would have been. If your system supports a warning on the guard codes when a prior guard is on file, set it.
6. Keep D9936 off the repair claim. On plans that carry the cleaning code, at least one national carrier bars billing it alongside D9942, including to the patient.

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