D8660 is the CDT code for a pre-orthodontic treatment examination to monitor growth and development — a periodic observation visit, at intervals set by the dentist, used to decide when orthodontic treatment should begin. It is an evaluation and monitoring service, not the start of active treatment.
Informational only — confirm the official CDT descriptor and your payers' rules independently. This is general guidance, not billing, coding, or clinical advice.
When to Use the D8660 Code
Report D8660 when a patient — typically a growing child or teen — is not yet ready for active orthodontic treatment but needs periodic monitoring of growth and dental development to determine the right time to begin. It is the recurring "let's watch and recheck" visit before any appliances are placed.
Code by the purpose of the visit. Don't confuse D8660 with a comprehensive or periodic oral evaluation (D0150/D0120), with limited or comprehensive orthodontic treatment (the D8010–D8090 series), or with the periodic treatment visit during active care (D8670). D8660 specifically describes pre-treatment growth monitoring, before active orthodontics has started.
Documentation & Clinical Scenarios
Because D8660 is an observation service, the chart should show genuine monitoring over time:
- Findings at the visit — developmental stage, eruption status, and any developing concerns being tracked.
- Comparison to prior visits — what changed since the last observation and why treatment is still being deferred.
- The interval set for the next recheck and the rationale for it.
- Any records taken — note whether photos, radiographs, or models were captured (these may carry their own codes).
Records such as panoramic films or diagnostic photos are generally billed separately under their own codes when taken. Keep dated notes for each observation so a string of D8660 visits clearly reflects ongoing monitoring rather than repeat billing of the same encounter.
Insurance & Billing Tips
- Verify the benefit type. Some plans treat D8660 under orthodontic benefits; others apply it to a diagnostic category — confirm before the visit.
- Check frequency limits. Plans often limit how often observation visits are covered (for example, once or twice a year).
- Watch for orthodontic-maximum impact. Confirm whether D8660 draws against a lifetime orthodontic maximum or a separate benefit.
- Separate the records. Bill any radiographs, photos, or models under their own codes rather than bundling them into the exam.
- Document the interval. A clear recheck schedule supports medical-necessity review for recurring observation visits.
Example Case
A 9-year-old presents with mixed dentition and a developing crossbite that the orthodontist wants to watch before intervening. Rather than starting treatment, the office schedules periodic growth-monitoring visits. At each visit the orthodontist records the developmental stage, compares it to prior notes, and sets the next recheck interval. Each visit is reported as D8660. When the dentition reaches the right stage, active treatment begins and is coded separately. Because each observation was dated and documented, the recurring D8660 claims are supported.
Patients call to ask "is it time for braces yet?" — not about D8660. DentalReception AI answers those calls 24/7, books the monitoring or consult visit live into your schedule, and captures insurance details, while clinical and coverage questions route to your team. See how it handles orthodontic consultation calls, or book a demo.
Frequently Asked Questions
What's the difference between D8660 and D8670?
Timing. D8660 is a pre-treatment growth-monitoring exam, used before any appliances are placed to decide when treatment should start. D8670 is the periodic treatment visit during active orthodontics — the recurring adjustment appointment once braces are on. One precedes treatment; the other happens during it, so they are never interchangeable.
Does D8660 include x-rays and photos?
Not necessarily. D8660 describes the observation and evaluation itself. Diagnostic records such as panoramic radiographs, cephalometric films, photos, or study models are generally reported under their own codes when taken. Document which records were captured at each visit, and bill them separately rather than assuming they're bundled into the monitoring exam.
How often will insurance cover a D8660 visit?
It varies by plan. Many payers limit observation visits to a set frequency, such as once or twice per benefit year, and some apply them to orthodontic rather than diagnostic benefits. Verify the frequency limit and benefit category before scheduling recurring monitoring visits so the patient isn't surprised if a visit falls outside the covered interval.
Do I need a pre-authorization for D8660?
A pre-estimate is less common for a monitoring exam than for active treatment, but it's still worth verifying coverage — especially the frequency limit and whether the visit draws against an orthodontic maximum. Confirming benefits before the visit lets you tell the family whether the recheck is covered and quote any out-of-pocket amount accurately.
Confirm the current CDT descriptor and your specific payer policies before billing — browse the full dental code library or see our insurance verification feature.