D0470 — Diagnostic Casts (Study Models)
D0470 covers models of the teeth made for diagnosis and treatment planning — physical stone casts or digital scans used to analyse the bite outside the mouth.
There is a limit to what can be assessed with a mirror and a patient's tongue in the way. Diagnostic casts solve that by taking the problem out of the mouth: an impression or an intraoral scan is turned into an accurate replica of the teeth that can be looked at from any angle, measured, mounted on an articulator to reproduce the bite, and — importantly — marked up and modified.
The code covers casts made specifically for diagnosis and planning. Models made as part of fabricating a crown, denture or orthodontic appliance are not billed separately; they are part of that restoration's fee.
What they are used to work out
Orthodontic planning is the biggest use: measuring crowding and arch length, classifying the bite, and predicting what space will be needed. Prosthodontic planning is the other — mounted casts show where the teeth actually meet, where the wear is coming from, how much vertical space is available for a restoration, and what a proposed full-mouth rehabilitation would have to achieve.
They also support a diagnostic wax-up: a model of the finished result, sculpted in wax or designed digitally, that lets patient and dentist look at the proposed outcome before anything irreversible happens. For anything involving multiple front teeth, that step is the difference between a shared plan and a surprise.
Physical versus digital
Traditional casts are stone models poured from an alginate or silicone impression. Digital models come from an intraoral scanner and live as files, which can be stored indefinitely, superimposed over time to measure wear or tooth movement, and sent anywhere instantly. The code is used for either.
Digital scanning has changed the patient experience more than the clinical one — no impression material, no gagging, immediate results. For tracking progressive wear or recession over years, the ability to superimpose scans from different dates is genuinely useful in a way stone models never were.
Coverage and when to expect it
Coverage is inconsistent. Some plans pay diagnostic casts at the diagnostic rate, some fold them into an orthodontic benefit, and many exclude them. Where casts are being made for a specific major treatment plan, expect to be asked to pay for them directly.
The reasonable question to ask is what the casts will change. For a complex restorative case, an orthodontic assessment, or a bite problem, the answer is usually substantial. For a single straightforward crown, it usually is not.
Questions about D0470
What are diagnostic casts used for?
Analysing the bite and the arches outside the mouth — measuring crowding, mounting the models to reproduce how the teeth meet, planning restorations, and building a wax-up of the proposed result.
Are digital scans billed as diagnostic casts?
Yes. The code covers models made for diagnosis and planning whether they are stone casts or digital scans.
Is D0470 covered by insurance?
Often not. Coverage is inconsistent and casts are sometimes only payable within an orthodontic benefit.
Why are models not billed with my crown?
Because models made in order to fabricate a restoration are part of that restoration's fee. D0470 is specifically for casts made to diagnose and plan.
Also known as: study models, diagnostic casts, dental impressions, wax-up, intraoral scan.