D2393 is the CDT code for a resin-based composite restoration on a posterior tooth involving three surfaces. Posterior teeth are premolars and molars. A mesial-occlusal-distal (MOD) composite on a molar is the most common clinical example. The surface count must be documented and must match what is billed.
Get help with D2393 claims →Last updated June 2026 · Reviewed by the PracticeAlpha billing team
Mesial-occlusal-distal restorations on premolars or molars are the most common three-surface scenario. Three distinct surfaces must be involved in the preparation.
Any combination of three surfaces on a posterior tooth qualifies: mesial-occlusal-facial, occlusal-distal-lingual, etc. The key is three clearly documented surfaces.
D2393 applies to posterior teeth. For a three-surface anterior composite use D2332. Tooth position determines the code family, not just the material.
Do NOT use D2393 for: Anterior teeth (use D233X codes). Two-surface posterior composites (use D2392). Four or more surface posterior composites (use D2394). Posterior amalgam restorations (use D2140, D2150, or D2160).
The surfaces billed on the claim must match the surfaces documented in the clinical chart. Billing D2393 when the chart documents a two-surface (MO or DO) preparation is an upcoding error. Reviewers check chart notes against claim surfaces. Document each surface involved before submitting, and ensure the tooth chart reflects exactly what was prepared and restored.
Many dental plans reimburse posterior composites at the amalgam benefit rate. The claim isn't denied outright, but reimbursement drops to the plan's amalgam allowance. The patient owes the balance if the fee agreement allows it. Inform patients before treatment when their plan has a posterior composite downgrade clause. This prevents disputes and confusion on the EOB.
Plans typically limit replacement restorations to once every one to three years per tooth. If a restoration was placed recently on the same surfaces, the claim will be denied on frequency grounds even if clinical conditions have changed. Submit a narrative with supporting x-rays when a replacement is genuinely warranted before the frequency window closes.
Current bitewing or periapical radiographs are standard documentation for multi-surface composites. The x-ray should show the extent of decay or the failing restoration being replaced. Without radiographic support, reviewers have no way to verify the clinical need for a three-surface restoration. Submit the most current radiograph available.
Explicitly list all three surfaces involved. The chart entry and the claim surfaces must match. Don't abbreviate; write out mesial, occlusal, distal (or whichever three apply).
Shows the extent of decay or the failing restoration. The radiograph is the primary objective evidence for multi-surface clinical need. Include the date taken.
State the diagnosis: caries, fracture, or failing restoration. Explain why three surfaces are involved. Objective findings support the code. Subjective patient complaints alone are not sufficient.
The ADA claim form surface field must show three surface codes matching the chart. A claim with only two surface codes but billing D2393 will be denied or downgraded.
If the plan downgrades posterior composites to amalgam, document that the patient was informed before treatment and accepted the potential balance due.
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Learn about our billing servicesD2393 is the CDT code for a resin-based composite restoration on a posterior tooth involving three surfaces. The three surfaces must each be documented in the clinical record and match the claim.
Premolars and molars are posterior teeth. In universal numbering: teeth 1-5, 12-16, 17-21, and 28-32. Canines and incisors are anterior and use the D233X codes.
D2392 is for two-surface posterior composites. D2393 is for three surfaces. D2394 covers four or more surfaces. The surface count in the clinical chart determines the correct code.
Common reasons: surface count mismatch between claim and chart, frequency limitations, missing radiographic evidence, and posterior composite downgrades to amalgam reimbursement rates.
Yes. A mesial-occlusal-distal composite on a molar involves three surfaces and D2393 is the correct code. Document all three surfaces in the clinical chart.
Most plans do not require pre-authorization for composite fillings. Larger restorations may be reviewed. Verify the patient's plan. When uncertain, submit pre-auth with radiographs before starting treatment.
D2160 is a three-surface amalgam on a posterior tooth. D2393 is the same surface count using composite material. Some plans pay D2393 at the D2160 amalgam rate on posterior teeth.
Search all CDT codes in our dental coding guide.