D9940 is the retired CDT code for an occlusal guard billed by report, deleted in the 2019 CDT update.
- When to use: It should no longer be billed, and a D9940 found on an old EOB or chart entry should be translated to the guard actually delivered before refiling.
- When not to use: A hard full-arch guard is D9944, a soft full-arch guard is D9945, and a hard partial-arch guard is D9946.
- Billing note: A claim with D9940 rejects as discontinued, so remove it from the fee schedule and saved night guard templates and refile under the current code.
Why D9940 is no longer valid
D9940 was the single “occlusal guard, by report” code, removed from the CDT code set in the 2019 update. As a by-report code it could not signal the guard’s material or arch coverage without a narrative, so the 2019 revision replaced it with three codes that carry that detail in the code itself.
The codes that replaced it
The three replacements split the old code by material (hard or soft) and coverage (full or partial arch):
- D9944 is a hard, full-arch occlusal guard, typically rigid acrylic.
- D9945 is a soft (pliable, cushioned), full-arch occlusal guard.
- D9946 is a hard, partial-arch occlusal guard.
Match the code to what the lab fabricated and what was seated.
They do not cover:
- An appliance made specifically to treat a TMJ disorder. That is generally D7880 (occlusal orthotic device, by report), and some plans route it through medical rather than dental.
- Reshaping the natural bite. That is an occlusal adjustment, D9951 (limited) or D9952 (complete), a different service from delivering a guard.
- Repairs or relines of an existing guard, which are handled differently depending on the carrier and appliance.
What to do if you still see D9940
D9940 usually comes back from a stale fee schedule line or a saved treatment-plan template that predates the 2019 change.
- Retire the D9940 line in the fee schedule and map its fee onto D9944, D9945, and D9946, labeled so staff can tell the material and arch apart.
- Update any night-guard or bruxism-appliance template so it posts a current code.
- If you are reading D9940 off an old EOB or chart entry, translate it to the appliance actually delivered before re-filing.
Top reasons occlusal-guard claims get denied
Even with the correct current code, guard coverage is plan-dependent. The recurring reasons:
- Not a covered benefit. Some plans exclude night guards and bruxism appliances entirely, or cover them only with specific documentation. The balance is patient responsibility.
- Frequency limit. Plans that cover guards often limit replacement to a set interval, so a new guard inside the window pends or denies.
- TMD versus bruxism framing. An occlusal guard (D9944 through D9946) is a different thing from a TMD orthotic (D7880). Filing the wrong one for the clinical intent draws a denial or a request for records.
- Medical versus dental routing. Some carriers send TMD-related appliances to the patient’s medical plan, so filing dental only can miss the benefit.
- Deleted code. The D9940 rejection itself, when an old template or fee schedule keeps posting it.
Example case
A patient with documented nighttime grinding is fitted for a rigid full-arch acrylic night guard. The front desk uses a saved “night guard” treatment plan that still posts D9940, and the claim rejects.
- Confirm the rejection reason: D9940 is a discontinued code.
- Match the appliance to a current code. A hard, full-arch guard is D9944.
- Re-file under D9944 with the fee mapped from the retired line item.
- Update the saved template and the fee schedule so D9940 stops reappearing.
- Verify the guard benefit and any frequency limit before delivery, and set the patient’s expectation, since many plans limit or exclude guards.
FAQs
- Is D9940 still a valid CDT code?
- No. D9940 (occlusal guard, by report) was deleted in the 2019 CDT update. A current claim submitted with D9940 will reject as an invalid or discontinued code. Use the replacement that matches the appliance: D9944 (occlusal guard, hard appliance, full arch), D9945 (soft appliance, full arch), or D9946 (hard appliance, partial arch).
- What replaced D9940?
- Three more specific codes replaced the single by-report code. D9944 is a hard, full-arch occlusal guard. D9945 is a soft, full-arch guard. D9946 is a hard, partial-arch guard. They split the old code by material (hard versus soft) and coverage (full versus partial arch), so the claim describes what was delivered without a by-report narrative.
- Why did my occlusal guard claim reject with D9940?
- Because D9940 no longer exists, so the clearinghouse or carrier flags it as a deleted or invalid procedure code. Re-file with D9944, D9945, or D9946 depending on material and arch coverage. Repeat rejections usually come from the code still sitting in your fee schedule or a saved treatment-plan template.
- What is the difference between an occlusal guard and an occlusal adjustment?
- An occlusal guard is a removable appliance the patient wears, usually at night, to protect teeth from grinding. Those are D9944, D9945, and D9946. An occlusal adjustment reshapes the natural tooth surface to correct the bite, and those are D9951 (limited) and D9952 (complete). Both mention occlusion, but they are different services.
- Is a guard for TMJ treatment billed with these codes?
- Plan-dependent. An appliance made specifically to treat a temporomandibular joint disorder is generally reported as D7880 (occlusal orthotic device, by report), not the D9944 through D9946 guard codes. Some plans route TMD appliances to medical coverage rather than dental. Verify which benefit applies and how the carrier wants the appliance documented before submitting.
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.