Occlusion Analysis Dental Code (D9950): Mounted Case

What D9950 covers

D9950 reports a diagnostic procedure: studying how a patient’s arches meet on models mounted to an articulator, and interpreting what that relationship shows. The records that make the mounting possible are part of the code: the facebow transfer that positions the maxillary cast, the interocclusal records and tracings that capture the jaw relationship, and a diagnostic wax-up when one is made as part of the workup.

The output is a finding, not a change to the patient. Nothing is reshaped or delivered. The analysis shows what the occlusion is doing and what a treatment plan has to account for. It typically comes before comprehensive restorative or prosthetic treatment, before a planned course of occlusal therapy, or in the workup of a patient with unexplained wear, mobility, or a diagnosed temporomandibular disorder.

It does not cover:

• Reshaping teeth. Selectively adjusting biting surfaces is D9951 for a single-visit adjustment at a specific tooth, site, or quadrant, or D9952 for a planned multi-visit course of occlusal therapy.
• The diagnostic casts. Those are D0470, the inclusion boundary offices get wrong most often (see below).
• An appliance. A night guard is D9944, D9945, or D9946 depending on material and arch coverage, and an orthotic made to treat a temporomandibular disorder is D7880, reported by report.

The mounting is the code

“Mounted case” is what separates D9950 from every other way an office looks at a bite. The analysis has to be done on models held in an articulator, with the patient’s jaw relationship transferred onto it. The facebow positions the maxillary cast relative to the hinge axis, and the bite record sets the mandibular cast against it. The articulator then reproduces the patient’s occlusal relationship closely enough to study contacts and excursive interferences that cannot be seen in the mouth.

Two things do not qualify:

• Articulating paper in the mouth. Marking contacts chairside is occlusal evaluation, done at nearly every restorative visit. Checking the bite at a periodic or comprehensive evaluation is part of that evaluation.
• Unmounted study models. Hand-held casts capture tooth shape, not the jaw relationship, so there is nothing for the analysis to be performed on.

What is included and what bills separately

Coding and adjudication give different answers here.

As CDT codes. The descriptor keeps the mounting records and the analysis inside D9950 and sends the diagnostic casts to D0470. A diagnostic wax-up made as part of the analysis is inside D9950. A complete workup before a full case is legitimately two lines, D0470 and D9950, and the adjustment that follows is a third. Tom Limoli has made this point in Dental Economics for years: the occlusal adjustment fee does not include the fee for the casts and the analysis, and all three are identified and billed separately.

As adjudication. Carriers commonly fold the workup into the treatment. Aetna’s occlusal adjustment policy states that any mounting of diagnostic casts, analysis, or diagnosis is integral to the complete adjustment, so on plans following that logic, D9950 and D0470 filed with D9952 add no payment. Separately, D0470 is most often reimbursed in connection with an orthodontic treatment plan and rarely pays outside of ortho.

Report what was performed, build the case fee assuming the analysis may not pay on its own, and discuss that with the patient before the workup.

D9950 and the adjustment codes

D9950 is diagnosis. D9951 and D9952 are treatment.

• D9951, occlusal adjustment limited. A single-visit adjustment at a specific tooth, site, or quadrant. It does not normally involve a mounted-case workup, so D9950 with D9951 is unusual and invites a question.
• D9952, occlusal adjustment complete. A planned, multi-visit course of occlusal therapy treating the occlusion as a system. This is the treatment D9950 exists to plan, and where both codes legitimately appear on the same case.

The two adjustment codes are separated by the scope of the treatment plan, not the number of teeth touched; limited and complete do not mean per tooth, per quadrant, and full mouth. A single visit taking down one high crown is limited even if several contacts are reduced. A diagnosed, sequenced course of occlusal therapy is complete even when the first appointment reaches only one quadrant. The mounted-case analysis is the evidence that a course of treatment was planned rather than improvised, which is what a reviewer looks for on a D9952 claim.

Coverage reality

Coverage on D9950 is thin, and denials come from benefit design far more often than from coding.

Frequently excluded outright. Utah’s PEHP plan lists D9950, D9951, and D9952 as not covered in its 2026 CDT code guide. A plan exclusion cannot be appealed on clinical grounds.

Often reviewed under a TMJ benefit rather than a diagnostic one. Delta Dental’s Covered California plan documents limit D9950, D9951, and D9952 together to one in 12 months, for diagnosed TMJ dysfunction, in the permanent dentition, and only for enrollees age 13 and older. The same documents exclude TMD treatment involving prosthodontics, orthodontics, or full or partial occlusal rehabilitation. On a contract like that, D9950 requires a TMJ diagnosis, shares a frequency clock with the adjustment codes, has an age floor, and may count against a separate TMJ maximum.

Sometimes a medical question. Where TMD coverage sits on the medical side, the workup may be reviewed there, and the two carriers can answer differently about the same case. Aetna’s TMD policy notes that most of its HMO plans exclude treatment of temporomandibular disorders and that the plan determines the scope of coverage. Find out which carrier owns the TMD benefit before submitting, rather than waiting out a dental denial and starting over.

Documentation that supports the claim

A reviewer wants to know whether the case was actually mounted and what the analysis found. A bare procedure line answers neither, so this code needs a narrative more than most. The record should carry:

• The mounting. The facebow transfer, the interocclusal record, and the articulator used. This is the evidence the procedure happened.
• The presenting problem. What led to a mounted analysis: wear facets, mobility or fremitus on specific teeth, a documented occlusal trauma finding, a diagnosed temporomandibular disorder, or a pattern of failed restorations.
• The finding. Which interferences were identified, in which movement. This separates a diagnostic procedure from a study model that got poured.
• What the finding changes. The treatment plan the analysis supports, whether occlusal therapy, a comprehensive restorative case, or a decision not to treat.
• The date performed. On a plan with a 12-month limit shared across the occlusal codes, this date drives the clock for the adjustment that follows.

A one-line narrative naming the finding does the work: “Mounted case analysis, facebow transfer and centric relation record, articulator-mounted; identified working-side interference #2 and #3 in left lateral excursion with wear facets and Class I mobility on #3.” A line reading only “D9950, occlusion analysis” looks to a carrier like the bite check inside the exam. A narrative template that prompts for the mounting records and the identified interference produces better claims than free text written a week later.

Practice software setup

The most common D9950 failure is not billing it at all.

1. Give the analysis a procedure code and a fee. Otherwise the facebow, the mounting, and an hour of clinical and lab time get absorbed into the exam or adjustment fee. If the practice does mounted-case work, it needs a line item with a fee, even on plans that will not pay it.
2. Post D9950 and D0470 as separate entries. One combined “study models and analysis” button guarantees one of them is never reported.
3. Keep D9950 apart from the adjustment codes. A pick list that groups all three under “occlusal” invites filing the analysis as an adjustment, which misreports the visit and uses up the adjustment’s frequency limit.
4. Default the posting to patient responsibility on plans that exclude it. Where the contract permits balance-billing a non-covered service, tell the patient before the workup and get agreement in writing, rather than aging an excluded code in insurance AR.

For how the procedure dates, the narrative, and the remarks field are filled in on the claim, see the ADA dental claim form guide.