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

When is a core buildup paid separately?

When the documented loss of tooth structure justifies it - Delta names 50% or more of the tooth lost and Cigna requires decay or fracture.

A core buildup (D2950) is paid separately when the documentation shows the tooth had lost enough structure that the crown could not be retained without rebuilding it — and not when the material is filling an undercut or shaping a preparation. Delta Dental publishes the clinical threshold in public: extensive loss of tooth structure, 50 percent or more, shown on images. Cigna requires decay or fracture that makes the buildup necessary to retain the final restoration. As of September 2026, Cigna bundled 260 of 563 core buildup lines (46.2%) across 16 practices as included in another procedure, which leaves 303 lines that were not bundled. Getting into that second group is a documentation and dating problem more often than a clinical one.

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" counts only lines denied as included in another procedure — a line not bundled may still have been denied for another reason, so this is not a payment rate. We publish no comparison rate for this code.

What the carriers' own policies say

Delta Dental's provider guidance "Core Buildup Dental Code: How to Avoid Claim Denials for Crowns" (December 2, 2022) names both the general condition and the specific clinical test:

"Under Delta Dental's processing policies, Delta Dental can make an allowance for a core build-up when there is extensive loss of tooth structure, documented in radiographic images or a narrative report, or when dental history suggests that it's needed, such as following root canal treatment."

"A core build-up is generally needed when the following conditions are met: A major part of the tooth's structure (50% or more) is fractured or carious. The preparation is at or below the gingival crest. Less than 3 mm of sound dentin remains vertically above the preparation line in opposing walls where the crown margins will be located."

The Cigna Dental Clinical Coverage Determination Guidelines, DPPO and Indemnity, 2026 (document 928339) states the allowable condition:

"When the tooth has decay or fracture that would require the D2950 (Core Buildup) to assist in retaining the final restoration (for example single crowns or bridge retainer crowns)."

Both carriers print the same limit on what a buildup is. Cigna, in the same policy: "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's national processing policies in the Delta Dental of New Jersey 2023 Participating Dentist Handbook say the same: the procedure "should not be reported when the procedure only involves a filler to eliminate any undercut, box form or concave irregularity in the preparation."

MetLife's Preferred Dentist Program (PDP) Resource Manual describes the two routes to an allowance:

"Core buildups may be payable based upon dental necessity when the permanent crown is inserted or as long as we have an approved pretreatment estimate."

And Cigna's DPPO Dental Office Reference Guide names the dating error that turns a payable buildup into a bundled one:

"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."

Why it depends on the plan

The threshold is the carrier's, but the sequencing rules that keep a buildup out of payment are per-carrier and they conflict. Cigna will not allow a buildup on the same date and same tooth as delivery of the final restoration, except for same-day CAD-CAM. MetLife wants it submitted with the seat date of the crown. United Concordia's Dental PPO Clinical Policy (last updated May 2026) caps it at one of D2950, D2952 or D2954 per tooth per five-year period and denies a buildup reported on or before an inlay, onlay, veneer, three-quarter crown or prefabricated crown as misreported.

A buildup can also be swallowed by the post rather than by the crown. Delta's guidance says that when D2954 is billed, "any composite, amalgam or build-up is included in the fee for D2954 and may not be billed separately", and Guardian's DentalGuard Preferred Network Dentist Manual, November 2020, Colorado state appendix, makes the buildup inclusive of a cast or prefabricated post and core, including one placed within 30 days.

What to do

• Take the pre-operative image before the preparation, and keep it labelled and dated. Delta's guidance is explicit that once the crown is on, the lost structure cannot be assessed.
• Write the narrative against the published thresholds: how much of the structure was fractured or carious, whether the preparation is at or below the gingival crest, and how much sound dentin remains.
• 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.
• Use a pre-treatment estimate for the crown and the buildup together when the plan supports one, and keep the approval with the claim.
• Do not bill the patient the buildup when it is bundled on a participating claim; that amount comes off under the network agreement. An out-of-network dentist has made no such agreement and may charge for it separately.

Numbers last refreshed September 2026.

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