D2150 is the CDT code for a two-surface amalgam (silver) filling on a primary or permanent tooth — a restoration that repairs decay or damage spanning two surfaces of a single tooth. It is reported per restoration, and the code is chosen strictly by the number of surfaces involved.
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 D2150 Code
Report D2150 when a tooth is restored with amalgam material and the restoration involves two surfaces — most often an occlusal surface plus one adjoining side (such as a mesial-occlusal or occlusal-distal filling on a back tooth). It applies to both primary and permanent teeth, since amalgam codes are not split by dentition.
Pick the code by surface count: D2140 is one surface, D2150 is two surfaces, D2160 is three, and D2161 is four or more. Don't confuse amalgam codes with the resin-based composite (tooth-colored) codes — a two-surface composite on an anterior tooth is D2331, and posterior composites have their own series. Code by the material actually delivered, since amalgam and composite are different procedures.
Documentation & Clinical Scenarios
A two-surface filling is routine, but the record should show what was treated and why:
- Tooth number and the specific surfaces restored (e.g., MO on tooth #30).
- The diagnosis — caries, fracture, or a failing prior restoration — that justifies the filling.
- The material (amalgam) and that two surfaces were involved.
- Supporting evidence such as a bitewing radiograph when interproximal decay isn't clinically obvious.
Report the single multi-surface code (D2150) once rather than two separate one-surface lines on the same tooth and date. Local anesthesia and the exam are reported under their own codes when applicable.
Insurance & Billing Tips
- Verify the restorative benefit. Most plans cover basic fillings at a coinsurance level (commonly around 80%) after any deductible.
- Surface count drives the fee. Two surfaces reimburse differently than one or three, so report exactly what was placed and avoid splitting one restoration into multiple lines.
- Check replacement frequency. Plans often limit how soon the same surfaces on the same tooth can be re-restored (e.g., once every 24 months).
- Confirm the deductible. Basic restorative work usually applies the plan deductible, affecting the patient's portion early in the benefit year.
- List surfaces clearly on the claim so the payer adjudicates the two-surface restoration correctly.
Example Case
A patient returns after a hygiene visit because the dentist flagged a back tooth with decay reaching the side. The dentist removes the decay and places a mesial-occlusal amalgam restoration. The visit is coded D2150 for tooth #30, surfaces MO, with a bitewing on file. Because benefits were verified and the two surfaces were reported accurately, the claim is paid at the expected coinsurance with no billing surprise.
Patients call about "a bigger filling on the side of my tooth" — not D2150. DentalReception AI answers and books those calls 24/7, captures insurance details for clean intake, and routes clinical and billing questions to your team. See how it handles filling calls, or book a demo.
Frequently Asked Questions
What's the difference between D2150 and D2160?
Surface count. D2150 is a two-surface amalgam filling, while D2160 is a three-surface amalgam filling on the same kind of tooth. The amalgam material is identical — only the number of surfaces restored changes the code. Report the single code that matches the actual restoration rather than stacking smaller-surface codes.
Can I bill two D2140 codes instead of one D2150?
No. When a single restoration covers two surfaces of the same tooth on the same date, it is reported once as D2150, not as two separate one-surface (D2140) lines. Payers routinely combine split surface codes into the correct multi-surface restoration, so coding it correctly up front avoids a down-code or denial.
How often will insurance cover a filling on the same tooth?
Many plans apply a replacement frequency limit, commonly allowing the same surfaces on the same tooth to be re-restored only once every 24 months or so. Re-treating sooner can be denied as a frequency conflict, so verifying the patient's history and benefit before treatment helps set an accurate estimate.
Do I need a pre-authorization for a D2150 filling?
Routine two-surface fillings usually don't require pre-authorization, but verifying the basic restorative benefit and any deductible beforehand lets you quote the patient an accurate out-of-pocket amount. Keep the diagnosis, tooth number, and surfaces documented in case of a post-payment review.
Confirm the current CDT descriptor and your specific payer policies before billing — browse the full dental code library or see our insurance verification feature.