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 belong to the code. That means the facebow transfer that positions the maxillary cast in space, the interocclusal records and tracings that capture the jaw relationship, and a diagnostic wax-up when one is made as part of working the case up.

The output is a finding, not a change to the patient. Nothing is reshaped, nothing is delivered. The code answers what the occlusion is doing and what a treatment plan would have to account for. It typically runs ahead of comprehensive restorative or prosthetic treatment, ahead of a planned course of occlusal therapy, or as part of working up a patient with unexplained wear, mobility, or a diagnosed temporomandibular disorder.

What it does not cover:

• Reshaping teeth. Selectively adjusting biting surfaces is D9951 if it is a single-visit adjustment at a specific tooth, site, or quadrant, or D9952 if it is a planned multi-visit course of occlusal therapy.
• The diagnostic casts themselves. Those are D0470. See below, because this is the inclusion boundary offices get wrong most often.
• 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 occlusal evaluation inside a routine exam. Checking the bite and marking contacts at a periodic or comprehensive evaluation is part of that evaluation.

The mounting is the code

“Mounted case” is the load-bearing part of the descriptor, and it 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 that articulator rather than approximated. That is what the facebow and the interocclusal record are for: the facebow positions the maxillary cast relative to the hinge axis, and the bite record sets the mandibular cast against it. Once that is done, the articulator reproduces the patient’s occlusal relationship closely enough to study contacts and excursive interferences that cannot be seen in the mouth.

Two things fail this test even though they look adjacent:

• Articulating paper in the mouth. Marking contacts chairside is occlusal evaluation. It happens at nearly every restorative visit, and it is not the procedure D9950 describes.
• Unmounted study models. Pouring casts and hand-holding them together captures tooth shape, not the jaw relationship. Without the mounting, there is nothing for the analysis to be performed on.

What is included and what bills separately

This boundary is worth reading twice, because coding and adjudication give different answers and both are useful to know.

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

As adjudication. Carriers commonly collapse the workup into the treatment. Aetna’s occlusal adjustment policy is explicit that any mounting of diagnostic casts, analysis, or diagnosis is considered integral to the complete adjustment. On a plan following that logic, D9950 and D0470 filed alongside D9952 do not add payment. They are absorbed. Separately, D0470 is most often reimbursed in connection with an orthodontic treatment plan and rarely pays outside of ortho.

Report what was performed. Just build the case fee on the assumption that the analysis may not carry its own payment, and have that conversation with the patient before the workup rather than after the EOB.

D9950 and the adjustment codes

D9950 is diagnosis. D9951 and D9952 are treatment. Keeping that straight fixes most of the confusion in this small family.

• D9951, occlusal adjustment limited. A single-visit adjustment at a specific tooth, site, or quadrant. A limited adjustment does not normally involve a mounted-case workup at all, so D9950 alongside 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 it is where the two codes legitimately appear on the same case.

The axis between the two adjustment codes is the scope of the treatment plan, not the number of teeth touched. Limited and complete are not the coding equivalents of per tooth, per quadrant, and full mouth. A single visit spent taking down one high crown is limited work even if several contacts get marked and reduced. A diagnosed, sequenced course of occlusal therapy is complete work even when the first appointment reaches only one quadrant. That matters to D9950 because the mounted-case analysis is the evidence that a course of treatment was planned rather than improvised, which is precisely the thing a reviewer looks for on a D9952 claim.

Coverage reality

Coverage on D9950 is thin and it fails for benefit-design reasons far more often than for coding reasons.

Frequently excluded outright. Utah’s PEHP plan lists D9950, D9951, and D9952 all as not covered in its 2026 CDT code guide. Plan exclusions are not appealable on clinical grounds, and there is no narrative that argues one away.

Often reviewed under a TMJ benefit rather than a diagnostic one. This is the pattern worth checking for on every verification. 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 cap the TMJ benefit tightly elsewhere, excluding TMD treatment that involves prosthodontics, orthodontics, or full or partial occlusal rehabilitation. On a contract built that way, D9950 is not a diagnostic-category service at all. It sits behind a TMJ diagnosis, shares a frequency clock with the adjustment codes, has an age floor, and may be subject to a separate TMJ maximum.

Sometimes a medical question. Where a plan carries TMD coverage on the medical side rather than the dental side, the workup may be reviewed there instead, and the two carriers can have different answers about the same case. Aetna’s TMD policy notes that most of its HMO plans exclude treatment of temporomandibular disorders and that the plan itself determines the scope of coverage. Ask which carrier owns the TMD benefit before you decide where the claim goes, rather than submitting to dental, waiting out the denial, and then starting over.

Documentation that supports the claim

A reviewer reading a D9950 claim is asking two things: was the case actually mounted, and what did the analysis find. A bare procedure line answers neither, which is why this code benefits from a narrative more than most.

The record should carry:

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

A one-line narrative naming the diagnostic finding does real work here: “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.” That answers the reviewer’s question. “D9950, occlusion analysis” does not, and it reads to a carrier like the occlusal check inside the exam.

What to get right in your PMS

The menus differ across Open Dental, Dentrix, Eaglesoft, Curve, and Carestream, but the setup is the same, and the failure this code has is unusual in that it is a failure to bill at all.

1. Give the analysis a procedure code and a fee. The most common D9950 outcome is no line. The facebow gets taken, the case gets mounted, an hour of clinical and lab time gets spent, and the work is absorbed into the exam fee or the adjustment fee because nobody ever built the code into the treatment plan. If the practice does mounted-case work, it needs a line item with a fee attached, even on plans that will not pay it.
2. Post D9950 and D0470 as separate entries. They are separate codes, and one combined “study models and analysis” button guarantees one of them is never reported.
3. Keep D9950 out of the adjustment slot. D9950 is diagnostic. D9951 and D9952 are treatment. A pick list that groups all three under “occlusal” invites filing the analysis as an adjustment, which misreports the visit and burns the adjustment’s frequency limit.
4. Attach a narrative template. Because the useful narrative here names a specific finding, a template prompting for the mounting records and the identified interference produces a better claim than free text written a week later.
5. Flag D9950 for verification at treatment planning. Include the question about which benefit category reviews it. That answer, not the yes or no, is what determines whether the claim has any chance.
6. Default the posting to patient responsibility on plans that exclude it. Where the contract permits balance-billing a non-covered service, say so before the workup and get it in writing. Aging an excluded code in insurance AR only delays the conversation.

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