D9940 was the CDT code for occlusal guards, sometimes called night guards or bruxism guards. It covered lab-fabricated appliances used to protect teeth from the effects of bruxism and clenching. D9940 was deleted from the CDT code set effective January 1, 2020 and replaced by three more specific codes: D9944, D9945, and D9946.
Last updated June 2026 · Reviewed by the PracticeAlpha billing team
Get help with D9940 claims →D9940 was the single CDT code for all occlusal guards. Before 2020, if a dentist fabricated a hard night guard, a soft night guard, a full-arch splint, or a partial coverage guard, the code was the same regardless of material or arch design. This limited the ability of payers to differentiate between appliance types and made accurate adjudication difficult.
Effective January 1, 2020, the ADA deleted D9940 and replaced it with three specific codes:
D9944 - Occlusal guard, hard appliance, full arch. Use this code when the guard is made of a rigid acrylic or hard resin material and covers all teeth in the arch. This is the most commonly billed replacement for the old D9940, as full-arch hard guards are the most frequently fabricated type.
D9945 - Occlusal guard, soft appliance, full arch. Use this code when the guard is made of a flexible or thermoplastic material and covers all teeth in the arch. Soft guards are often used for patients with mild bruxism or for athletic mouth guard-type applications for bruxism protection.
D9946 - Occlusal guard, hard appliance, partial arch. Use this code when the guard is hard material but covers only part of the arch rather than all teeth. Partial arch hard guards are less common but do occur in specific clinical situations.
There is no current code for a soft partial arch guard. If a soft partial arch guard is fabricated, consult the applicable CDT manual for the appropriate reporting option for that situation.
Using D9940 on a current claim will result in denial. Payers updated their systems when the code was retired. Any claim submitted today with D9940 will be rejected as an invalid or inactive code. Use the appropriate replacement code that matches the type of guard delivered.
Some practices that did not update their fee schedules in 2020 still have D9940 listed as an active code in their software. Claims go out with an invalid code and deny. Audit your fee schedule for D9940 and remove or inactivate it. Replace it with entries for D9944, D9945, and D9946 with the appropriate fees for each type of guard your practice delivers.
The replacement codes are material-specific and coverage-specific. Billing D9944 for a soft guard, or D9945 for a hard guard, is a code mismatch that can trigger a denial or audit. The code must match what was actually fabricated. Confirm with your lab or your in-house fabrication process before billing. Document the appliance type in the clinical record.
Occlusal guard claims under D9944 through D9946 require the same clinical justification that D9940 required. The record should document a diagnosis such as bruxism, clenching, or a temporomandibular disorder that indicates the need for the appliance. Many payers will request additional documentation or prior authorization. Having a clear diagnosis in the chart prevents delays and denials.
Some older payer contracts and EOBs still reference frequency limitations that were originally established for D9940. When these contracts were updated to recognize D9944 through D9946, the frequency limits may not have been clearly communicated. If a claim is denied for frequency, check whether the payer's limitation was originally set under D9940 and whether it was properly transitioned to the replacement codes. Appeal with documentation if the limitation is being misapplied.
Document the clinical diagnosis: bruxism, clenching, temporomandibular disorder, or other condition indicating the need for occlusal protection. A diagnosis code alone is not enough. The chart note should describe the clinical findings that led to the recommendation for a guard.
Record whether the guard is hard or soft, and whether it covers the full arch or partial arch. This determines which replacement code (D9944, D9945, or D9946) is correct. The code on the claim must match the appliance in the chart.
If the guard is lab-fabricated, keep the lab prescription and any work authorization. If fabricated in-house, document the materials and method. This supports the code selection and provides an audit trail.
Document the delivery visit: that the guard was delivered, adjusted, and that the patient was instructed on use and care. Some payers track delivery date separately from the fabrication date.
Check the patient's plan for occlusal guard authorization requirements. If pre-auth is required, submit it before delivering the appliance. Include the auth number on the claim.
Getting denials on occlusal guard claims? We help practices update coding, documentation, and submission workflows.
Learn about our billing servicesD9940 was the CDT code for occlusal guards (night guards, bruxism guards). It covered lab-fabricated appliances used to protect teeth from bruxism and clenching. D9940 was deleted from the CDT code set effective January 1, 2020 and is no longer a valid billing code.
The ADA retired D9940 in 2020 because a single code was insufficient to differentiate between appliance types. The replacement codes (D9944, D9945, D9946) allow billing to specify the material (hard or soft) and arch coverage (full or partial), which supports more accurate payer adjudication.
D9940 was replaced by D9944 (hard appliance, full arch), D9945 (soft appliance, full arch), and D9946 (hard appliance, partial arch). Choose the code that matches the type of guard fabricated and delivered to the patient.
The claim will be denied. D9940 is an inactive code and payers do not recognize it. Update your practice management software to use D9944, D9945, or D9946 as appropriate. Remove D9940 from your active code list if it is still there.
Coverage depends on the patient's plan. Many plans carry over the same occlusal guard benefit that previously applied to D9940, now applied to D9944 through D9946. Some plans require prior authorization or a diagnosis narrative. Always verify current benefits under the active codes before delivering the appliance.
Document the clinical diagnosis supporting the guard, the type of appliance (material and arch coverage), the lab prescription or fabrication record, and the delivery visit. Prior authorization may be required depending on the patient's plan. The code on the claim must match the appliance type documented in the chart.
Search all 206 CDT codes in our dental coding guide.