Claims · Updated 2026-09-08 · 5 min read

Why was my core buildup denied as included in the crown?

Cigna denied 46.2% of core buildup lines as included in another procedure. Carriers pay D2950 only when the documented loss of tooth structure justifies it.

A core buildup (D2950) is denied as included in the crown when the carrier does not see evidence that the tooth needed structural rebuilding to hold the crown. Every carrier that publishes a rule treats the buildup as part of the crown by default and pays it separately only by exception. As of September 2026, Cigna bundled 260 of 563 core buildup lines — 46.2%, across 16 practices — the most bundled restorative code we measure. Two things drive the denial beyond clinical necessity: billing on the preparation date rather than the seat date, and submitting without an image or narrative that shows how much tooth was lost. Where the dentist is in network the buildup is a write-off, not a patient balance; an out-of-network dentist may charge for it separately.

What we measured

Every remittance line for D2950 at Cigna, all dates, measured on 8 September 2026 across 37 practices and more than 170 payers. "Bundled" means the line was denied as included in another procedure. We publish no comparison rate for this code.

What the carriers' own policies say

The Cigna Dental Clinical Coverage Determination Guidelines, DPPO and Indemnity, 2026 (document 928339) lists when a buildup is not allowable:

"In the absence of major decay or fracture of the tooth. • When a buildup is not necessary to aid in the retention of the final restoration. • When completed on the same date of service and same tooth as delivery of the final restoration. Exceptions may be considered for indirect restorations made with CAD-CAM (same day) technology. • When completed on the same date of service and same tooth as a post and core … • When performed in conjunction with any intracoronal restorations (inlays, direct restorative fillings)"

Cigna also prints the definitional line the whole subject turns on. D2950 "Refers to building up of coronal structure when there is insufficient retention for a separate extra coronal restorative procedure. A core buildup is not a filler to eliminate any undercut, box form, or concave irregularity in a preparation."

Delta Dental's provider guidance "Core Buildup Dental Code: How to Avoid Claim Denials for Crowns" (December 2, 2022) gives the exact sentence an office reads on the remittance:

"5BU. The documentation doesn't show a significant loss of tooth structure. The fee for the build-up is included in the fee for the completed restoration."

and explains the evidentiary problem plainly:

"Since we can't determine the amount of tooth that has been lost underneath the crown, the buildup will be included in the fee for the crown."

Liberty Dental Plan's National Clinical Criteria Guidelines and Practice Parameters, 2026 puts the burden in one sentence:

"The treating dentist must provide evidence that the tooth requires additional structural support to retain and support a crown. If this evidence is not provided, the service will be considered part of the crown restoration."

MetLife's Preferred Dentist Program (PDP) Resource Manual describes what it wants to see instead of a denial:

"A Core Buildup should be submitted with a pretreatment estimate for the crown or with the service date of the final crown with a dated, labeled pre-treatment x-ray to ensure accurate determination of benefits."

The United Concordia Dental PPO Clinical Policy (last updated May 2026) adds a sequence rule and a frequency cap: a buildup is "Denied as MISREPORTED when reported on the same date or prior to an Inlay …, Onlay …, Veneer …, 3/4 crown …, Prefabricated crown … on the same tooth", and only one of D2950, D2952 or D2954 is allowed per tooth per five-year period.

Why it depends on the plan

The carriers disagree on the single most common scenario. Cigna will not allow a buildup delivered on the same date as the final restoration, with an explicit exception for same-day CAD-CAM crowns. MetLife wants the buildup submitted with the seat date of the final crown. So the same claim, billed the same way, is correct at one carrier and denied at the other — which is why the plan's own rule, not the coding habit, has to drive the submission.

Cigna's DPPO Dental Office Reference Guide names the billing behaviour that causes the denial outright:

"Submitting procedures on preparation dates will cause related services submitted with the same date of service to be denied as inclusive (i.e., D2950). If a CAD/CAM system was used for same-day placement, you should note this on the claim form."

What to do

• Take and keep a pre-operative image that shows the missing tooth structure before the preparation. After the crown is on, no image can show it, and Delta says so explicitly.
• MetLife wants the buildup submitted with the crown's seat date; Cigna denies a buildup dated the same day the final restoration is delivered unless it was a same-day CAD-CAM crown, so date the buildup to the day it was actually placed.
• Send a pre-treatment estimate for the crown and the buildup together where the plan allows one. MetLife names the approved pre-treatment estimate as an alternative path to payment.
• Write the narrative in the terms the carriers use: how much of the coronal structure is gone, whether the preparation reaches the gingival crest, and how much sound dentin remains.
• Do not bill the patient for a bundled buildup on a participating claim. Delta's own guidance tells dentists not to transfer financial liability to the patient for inclusive services. An out-of-network dentist has no such contract and may charge for it separately.

Numbers last refreshed September 2026.

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