The short version
# D9310 Dental Code: Diagnostic Consultation
D9310 reports a diagnostic consultation by a dentist or physician other than the practitioner who requested the opinion. It includes an oral evaluation directed at a specific problem and may lead to diagnostic or therapeutic services. A referral alone doesn't prove the consultation, and a routine new-patient exam isn't automatically D9310.
- Bill D9310 when another dentist, physician, or appropriate source requests the practitioner's opinion or advice about a specific dental problem.
- The consulted practitioner is different from the requesting practitioner.
- The consultation includes an oral evaluation. Record the question, findings, opinion, and communication back to the requester.
- Use D0140 for a limited problem-focused evaluation when the visit isn't a requested outside consultation.
- D9430 is an office visit for observation during regular hours with no other service performed. It doesn't describe a diagnostic second opinion.
- In a worked claim, a $250 fee becomes a $180 allowable. The plan pays $144 at 80%, the patient owes $36, and the office adjusts $70.
What is D9310?
D9310 is a practitioner-to-practitioner consultation service. The public ADA code-action material describes an encounter in which another practitioner or appropriate source asks for an opinion or advice on evaluation or management of a specific problem.
| Fact | D9310 |
|---|---|
| CDT category | Adjunctive general services |
| Request | From another dentist, physician, or appropriate source |
| Service | Diagnostic opinion and oral evaluation |
| Follow-on care | Consultant may initiate diagnostic or therapeutic services |
| Public fee references | Oregon Medicaid: $73.05; Washington Medicaid: $63.60 to $90.86 across program columns in 2025 |
When do you bill D9310?
Use D9310 when the record shows a requested outside diagnostic opinion.
- Identify the requesting practitioner or source.
- State the specific clinical question.
- Perform the oral evaluation needed for the opinion.
- Record findings, diagnosis, advice, and recommended next steps.
- Send the consultation result to the requester and retain that communication.
D9310 vs D0140 and D9430
The visit's origin and purpose separate these services.
| D0140 | D9310 | D9430 | |
|---|---|---|---|
| Trigger | Patient presents with a focused problem | Another practitioner or source requests an opinion | Observation visit during regular hours |
| Includes evaluation | Limited, problem-focused | Oral evaluation within consultation | No other service performed |
| Outside requester required | No | Yes | No |
| Main output | Diagnosis and treatment plan | Opinion or advice returned to requester | Observation record |
What does insurance actually do with D9310?
A public Delta California certificate lists D9310 as a covered code but doesn't state a universal frequency on that line.
- Office fee: $250
- Contracted allowable: $180
- Contractual adjustment: $70
- Plan payment at 80%: $144
- Patient balance: $36
Why does D9310 get denied?
- The record doesn't identify a requesting practitioner or source.
- The visit appears to be a routine evaluation rather than a consultation.
- Another exam falls inside the payer's grouped frequency.
- Referral or specialist authorization is missing.
- Same-day diagnostic or therapeutic services cause the plan to include the consultation.
What documentation gets D9310 paid?
- Name the requesting practitioner or appropriate source.
- State the requested diagnostic question.
- Document the oral evaluation and relevant findings.
- Record the consultant's diagnosis, advice, and management options.
- Keep the report sent back to the requester.
- Separate any additional diagnostic or treatment services delivered.
Common questions about D9310
Does D9310 require a referral?
Yes, the service needs a request for an opinion or advice from another practitioner or appropriate source. Document who requested it, the specific clinical question, records supplied, evaluation performed, and report returned. A patient simply seeking another exam doesn't by itself establish this consultation structure.
Can a general dentist bill D9310?
Yes. The public code language isn't limited to a specialty credential. The key is that the billing dentist is providing the requested diagnostic consultation and is different from the requesting practitioner. The record must still identify the requester, question, evaluation, opinion, and communication back.
Can treatment occur on the consultation date?
Yes. The ADA material says the consultant may initiate diagnostic or therapeutic services. Report each service actually delivered, keep the consultation opinion distinct from the additional procedure, and apply the payer's referral, same-day, and bundling terms. Coverage doesn't decide whether the clinical services occurred.
Is D9310 the right code for every second opinion?
Only when another practitioner or appropriate source requested an opinion about a specific problem and the consulted practitioner completed the diagnostic consultation. If the patient independently seeks a focused evaluation, D0140 may fit instead. Document the request and report so “second opinion” isn't the only support.
Close the referral loop
Don't file D9310 until you've matched the specialist's written opinion to the referring dentist's request.
Sources
- ADA, public D9310 code-action material
- ADA, Glossary of Dental Terms
- ADA, specialty referrals
- ADA, frequently asked questions regarding dental codes
- Delta Dental, 2025 California certificate of coverage
- Washington Medicaid, July 2025 dental fee schedule
- Oregon Medicaid, June 2025 fee schedule
- ADA, Medicaid fee schedule index
CDT codes and nomenclature are copyright © American Dental Association. This guide explains the code in plain language; the current CDT manual is the authoritative source.
