The short version
# D2950 Dental Code: Core Buildup Before a Crown
D2950 is the CDT code for rebuilding enough of a damaged tooth to retain a planned crown, with any required pins included in the procedure. It applies when decay, fracture, or prior treatment leaves insufficient sound structure for crown retention. A routine filler placed only to smooth the crown preparation isn't a separate buildup.
- Bill D2950 when the dentist places restorative material to rebuild an anatomical core because the remaining tooth can't retain the planned crown.
- Don't report D2950 for material that only fills an undercut, box, or concavity created or addressed during ordinary crown preparation.
- Pins are already included in D2950. A separate pin-retention line doesn't belong with the same buildup.
- Delta Dental's published criteria look for extensive structure loss and list a 50% loss threshold, a preparation at or below the gingival crest, and less than 3 mm of sound opposing dentin above the margin.
- In a worked claim, a $300 fee becomes a $220 allowable. At 50%, the plan pays $110, the patient owes $110, and the office adjusts $80.
- Send a preoperative periapical image, tooth number, structure-loss estimate, cause of the loss, crown plan, and a narrative explaining why routine preparation wasn't enough.
What is D2950?
D2950 reports placement of material that rebuilds the missing coronal tooth structure needed to hold a crown. The core creates retention and resistance that the damaged tooth doesn't provide on its own. The code includes pins when pins are required, so the office reports one buildup procedure for that tooth.
| Fact | D2950 |
|---|---|
| CDT category | Restorative |
| Unit | Per tooth |
| Planned restoration | A crown will be placed |
| Clinical reason | Insufficient strength or retention from remaining tooth structure |
| Included item | Any pins required for the buildup |
| Public fee reference | DC Medicaid listed $220 for D2950 as of May 17, 2025 |
The ADA's D2950 guidance draws the key line: the buildup must restore missing anatomy needed for crown retention.
When do you bill D2950?
Bill D2950 when the preoperative condition shows substantial loss of tooth structure and the dentist must build a core before the tooth can retain a crown.
- Identify decay, fracture, failed restoration, or prior endodontic access that removed important coronal structure.
- Measure or estimate the remaining sound tooth structure before the crown preparation hides the starting condition.
- Record why the remaining walls don't provide adequate retention and resistance.
- Place the buildup as a distinct restorative step for the planned crown.
- Include any necessary pins in D2950 rather than billing a second pin code.
Delta Dental's clinical criteria give reviewers a concrete test. Delta generally looks for at least 50% structure loss, a preparation at or below the gingival crest, and less than 3 mm of sound dentin remaining vertically in opposing walls above the planned crown margin.
D2950 vs D2954 and the crown preparation
The amount and location of remaining tooth structure, plus endodontic status, decide whether the office has a separately reportable foundation procedure.
| Crown preparation only | D2950 | D2954 | |
|---|---|---|---|
| Starting condition | Crown preparation needs small undercuts or irregularities filled | Coronal structure is too weak or incomplete to retain the crown | Endodontically treated tooth needs a prefabricated post and core |
| Main work | Prepare the tooth for the crown | Rebuild the anatomical core | Place the prefabricated post and core foundation |
| Pins or post | No separate pin line for routine prep | Pins included if used | Prefabricated post is central to the service |
| Separate benefit | Commonly included with crown prep | May pay when documentation supports need | Evaluated under post-and-core criteria |
The error that causes most denials is calling every base under a crown D2950. The ADA's bundling guidance says bases and liners are components of restorations, and D2950 already includes any pins. The chart should explain the missing structure, not only say “buildup placed.”
The D2740 crown guide covers the full-coverage restoration and its own downgrade rules.
What does insurance actually do with D2950?
Payers often review D2950 with the crown image and narrative. Delta says it can allow the buildup when images or a report show extensive structure loss, including a need suggested by root canal history. Delta also treats a buildup as inclusive with inlays, onlays, three-quarter crowns, and veneers under its processing policy.
A published Delta Dental Nevada plan limits D2950 to one per 36 consecutive months and considers it only when the crown lacks enough retention. That plan also excludes a filler used only for undercuts or preparation irregularities. Check the patient's plan because frequency and bundling language differ.
- Office fee: $300
- Contracted allowable: $220
- Contractual adjustment: $80
- Plan payment at 50%: $110
- Patient coinsurance: $110
Why does D2950 get denied?
- The preoperative image doesn't show extensive loss of coronal tooth structure.
- The note says “buildup” but doesn't state the decay, fracture, failed restoration, or retention problem.
- The material only filled an undercut, box, or concavity associated with routine crown preparation.
- The office billed a separate pin code even though D2950 includes required pins.
- The buildup falls inside the plan's frequency limit or the planned restoration isn't a covered crown.
If the EOB bundles the buildup, check whether the payer found a coding component or applied a plan limitation.
What documentation gets D2950 paid?
- Identify the tooth and the planned crown code.
- Attach a dated, unobstructed preoperative periapical image.
- State the cause and extent of structure loss, including the estimated percentage or missing walls and cusps.
- Record the remaining sound dentin and why it couldn't retain the crown.
- Describe the buildup material and any pins without reporting the pins separately.
- Include endodontic history and current periapical status when prior root canal treatment affects the need.
Common questions about D2950
Can D2950 be billed on the same tooth as a crown?
Yes, when the core buildup is a separate, necessary service and the remaining tooth couldn't retain the crown without it. The crown and buildup describe different work. Keep preoperative evidence of missing tooth structure and explain why ordinary crown preparation wouldn't provide adequate retention and resistance.
Does every root-canal-treated tooth need D2950?
No. Root canal history can support the need, but access alone doesn't prove that a separate buildup was required. Delta says the images or narrative must show extensive structure loss or another retention problem. Document the remaining walls and the actual foundation placed.
Can you bill D2951 for pins with D2950?
No. D2950 includes any pins required for the core. The ADA lists separate pin billing with a core buildup as an inconsistent code combination. D2951 applies to pin retention with a restoration under its own rules, not as an add-on to D2950.
Is D2950 included in the crown fee?
It's included when the material only corrects ordinary preparation form. A true buildup that reconstructs missing anatomy for retention is a distinct procedure, although a plan can limit or bundle the benefit. Read the contract and EOB before deciding what amount can move to the patient.
Review the next crown image now
Don't file D2950 until you've connected the missing tooth structure to the crown's retention problem.
Sources
- ADA, D2950 core buildup guidance
- ADA, bundling of procedure codes
- ADA, Responding to Claim Rejections
- Delta Dental, clinical criteria and processing policies
- Delta Dental, core buildup claim documentation
- Delta Dental, Nevada plan benefits and limitations
- Washington, DC Medicaid fee schedule, May 17, 2025
- Oregon Medicaid, June 2025 fee schedule
- FAIR Health Consumer, dental cost lookup
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.
