D2394 dental code: four-surface posterior composite.

D2394 is the CDT code for a resin-based composite restoration on a posterior tooth involving four or more surfaces. Posterior teeth are premolars and molars. All four surfaces must be documented individually in the clinical chart. This is the highest surface-count posterior composite code and carries more scrutiny than D2391 through D2393.

Get help with D2394 claims →

Last updated June 2026 · Reviewed by the PracticeAlpha billing team

Code
D2394
Category
Restorative
Tooth Type
Posterior only
Coverage
Basic (70-80%)

When to use D2394

Four or more surfaces on a molar

Extensive decay or a large failing restoration that involves four or more distinct surfaces of a premolar or molar. All surfaces must be in the preparation and restoration.

MODFL or similar large preparations

Mesial-occlusal-distal-facial-lingual and similar extended preparations on posterior teeth. Each surface must genuinely be part of the preparation boundary, not incidentally brushed.

When composite is chosen over crown

When clinical judgment supports composite over full coverage. Document the rationale. Some reviewers will question whether a crown (D2740, D2750) is more appropriate for four-surface involvement.

Do NOT use D2394 for: Anterior teeth, even canines in some plan interpretations (use D2335 for anterior four-surface or incisal angle). Three-surface posterior composites (use D2393). Posterior amalgam restorations (use D2140, D2150, or D2160). Situations where the preparation genuinely involves fewer than four surfaces.

Why D2394 claims get denied

Surface count not supported by documentation

D2394 claims draw more scrutiny than lower-surface composite codes because four or more surfaces implies extensive tooth destruction. Reviewers look for pre-operative radiographs that show matching extent of decay or failing restoration. Clinical notes must name each surface. If the x-ray shows a small Class II lesion and you billed D2394, the claim will be questioned.

Posterior composite downgrade

Many plans reimburse posterior composites at the amalgam benefit rate regardless of surface count. This applies to D2394 just as it does to D2391 through D2393. The claim is paid at a lower reimbursement. Inform patients before treatment when their plan has a posterior composite downgrade policy. Document that conversation in the chart.

Crown necessity question

Some payers will question whether a four-surface posterior composite is appropriate or whether a crown is the indicated treatment. A claim may be downgraded, denied, or sent for review. A strong clinical narrative explaining why composite is the preferred treatment approach in this case, and why full coverage is not required, reduces that risk.

Frequency limitation

Replacement restorations on the same tooth within a plan's frequency window will be denied. Check the patient's history. When a replacement is clinically necessary before the frequency limit, submit a narrative with the pre-operative radiograph and a description of failure mode (recurrent decay, fracture, secondary caries under existing restoration).

Documentation checklist for D2394

All four or more surfaces named explicitly

The chart entry must list every surface in the preparation. Abbreviations are fine in a consistent charting system, but the surfaces must be countable and match the claim.

Pre-operative radiograph

A periapical or bitewing showing the extent of decay or the failing restoration. The radiographic picture should be consistent with a four-surface preparation.

Clinical rationale for composite over crown

If the clinical record can support why composite was chosen over full coverage, include it. This preempts plan reviewer questions about treatment necessity and appropriateness.

Intraoral photos (strongly recommended)

For four-surface posterior composites, photos showing the pre-operative condition add objective evidence that is hard to dispute. Include them whenever available.

Patient downgrade notification

If the plan pays posterior composites at amalgam rates, document that the patient was informed and accepted potential balance due before treatment began.

Posterior composite claims getting downgraded or questioned? We fix the coding, documentation, and follow-up that cause it.

Learn about our billing services

Related composite and restorative codes

D2391 Resin-based composite, one surface, posterior
D2392 Resin-based composite, two surfaces, posterior
D2393 Resin-based composite, three surfaces, posterior
D2335 Resin-based composite, four or more surfaces or incisal angle, anterior
D2740 Crown, porcelain/ceramic (alternative when four-surface composite is borderline)
D2950 Core buildup, including any pins (if used with a crown instead)

D2394 FAQ

What is D2394 dental code?

D2394 is the CDT code for a resin-based composite restoration on a posterior tooth covering four or more surfaces. All surfaces must be documented in the clinical chart. Posterior teeth are premolars and molars.

What is the difference between D2394 and D2393?

D2393 covers three surfaces on a posterior tooth. D2394 covers four or more surfaces. The surface count in the clinical chart determines the correct code. Billing D2394 for three surfaces is upcoding.

What is the difference between D2394 and D2335?

D2394 is for four-surface composites on posterior teeth. D2335 is for four-surface composites or incisal angle restorations on anterior teeth. Tooth position (anterior vs. posterior) determines the code family.

Why do D2394 claims get denied?

Common reasons: surface count not supported by radiographs or notes, plans questioning whether a crown is more appropriate, frequency limitations, and posterior composite downgrades to amalgam reimbursement.

Is D2394 at higher audit risk than D2393?

Yes. Four-surface posterior composites imply extensive tooth destruction and attract more scrutiny. Pre-operative radiographs, detailed notes, and intraoral photos are important to support the claim.

Can D2394 be used when a crown would also be appropriate?

Yes, but document why composite was chosen. Some plans will question or downgrade a four-surface posterior composite without a clear rationale for why full coverage was not used.

Looking for another code?

Search all CDT codes in our dental coding guide.

Browse all CDT codes →