D9940 Dental Code: Retired Occlusal Guard Code (Use D9944)

Why D9940 is no longer valid

D9940 was the older, single “occlusal guard, by report” code. It was removed from the CDT code set in the 2019 update. Because it was a by-report code, it described the appliance too broadly, so it couldn’t signal the material or the arch coverage without a narrative. The 2019 revision replaced it with three specific codes that carry that detail in the code itself.

A current claim filed with D9940 rejects as a discontinued or invalid procedure code, and there is nothing to appeal. The claim gets re-filed with the replacement that matches the appliance delivered.

The codes that replaced it

The three replacements split the old code by two axes: material (hard or soft) and coverage (full arch or partial arch).

• D9944 is a hard, full-arch occlusal guard, typically rigid acrylic.
• D9945 is a soft, full-arch occlusal guard.
• D9946 is a hard, partial-arch occlusal guard.

They do not cover:

• An appliance made specifically to treat a TMJ disorder. That’s generally D7880 (occlusal orthotic device, by report), and some plans route it through medical rather than dental.
• Reshaping the natural bite. That’s an occlusal adjustment: D9951 (limited) or D9952 (complete). It is a different service from delivering a guard.
• Repairs or relines of an existing guard, which have their own handling depending on the carrier and appliance.

How to pick the replacement code

Two questions decide it:

1. Hard or soft? A rigid acrylic guard is hard (D9944 or D9946). A pliable, cushioned guard is soft (D9945).
2. Full arch or partial arch? A guard covering the full arch is D9944 (hard) or D9945 (soft). A hard guard covering only part of the arch is D9946.

That covers the common combinations. Match the code to what the lab actually fabricated and what was seated, the same discipline you’d apply to any material-specific code.

What to do if you still see D9940

D9940 usually resurfaces from a stale line in the office fee schedule or a saved treatment-plan template that predates the 2019 change. Both quietly re-inject the dead code into new claims.

• Retire the D9940 line item in the fee schedule and map its fee onto D9944, D9945, and D9946.
• Update any night-guard or bruxism-appliance template so it posts a current code.
• If you’re reading D9940 off an old EOB or an old chart entry, translate it to the appliance actually delivered before re-filing anything.

Top reasons occlusal-guard claims get denied

Even with the correct current code, guard claims are coverage-sensitive. Plan-dependent, but the recurring reasons:

1. 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.
2. Frequency limit. Plans that do cover guards often limit replacement to a set interval, so a new guard inside the window pends or denies.
3. TMD versus bruxism framing. A guard billed as a D9944 through D9946 occlusal guard 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.
4. Medical versus dental routing. Some carriers push TMD-related appliances to the patient’s medical plan. Filing dental-only can miss the benefit.
5. Deleted code. The D9940 rejection itself, when an old template or fee schedule keeps injecting the discontinued code.

Example case

A patient with documented nighttime grinding is fitted for a rigid full-arch acrylic night guard. The front desk pulls up a saved “night guard” treatment plan that still posts D9940, and the claim rejects.

Billing steps:

1. Identify the rejection reason: D9940 is a discontinued code.
2. Match the appliance to a current code. A hard, full-arch guard is D9944.
3. Re-file the claim under D9944 with the fee mapped from the retired line item.
4. Fix the root cause: update the saved template and the fee schedule so D9940 stops reappearing.
5. Verify the guard benefit and any frequency limit, and set the patient’s expectation, since many plans limit or exclude guards.

What to get right in your PMS

1. Remove D9940 from the fee schedule and templates. A deleted code that’s still stored will keep re-injecting itself into claims.
2. Map fees onto D9944, D9945, and D9946. Keep the material and arch-coverage distinctions clear so staff pick the right one.
3. Keep guard codes separate from adjustment codes. D9944 through D9946 are appliances; D9951 and D9952 are bite reshaping. They are not interchangeable.
4. Flag TMD appliances for a D7880 and medical-routing check. A guard for a TMJ disorder is often a different code and sometimes a different benefit.
5. Verify the guard benefit and frequency before delivery. Coverage is plan-dependent, and setting the financial expectation up front keeps balances out of aging AR.