Claims · Updated 2026-09-09 · 6 min read

Should I appeal a denied core buildup?

The wording of the denial answers it. "We could not determine" is a document you can send; "the fee is included in the crown" is a decision already made.

Read the denial wording before you decide. A core buildup (D2950) is refused in two completely different ways, and only one of them is an appeal. When the carrier says it could not determine benefits, nothing has been decided — it could not see the tooth, and the remedy is the image or the narrative it named. When the carrier says the fee for the buildup is included in the fee for the completed crown, it has decided: it read your documentation and concluded the buildup was a filler rather than a retention procedure. Those two denials look alike on a remittance and cost different amounts of staff time. Kaylie does not measure appeal outcomes — a carrier's redetermination arrives as a new claim, so this article publishes no overturn rate.

What we measured

Denied core buildup lines by carrier and the reason the payer stated, measured 8 September 2026 across the practices Kaylie serves. A cell appears only where at least five practices and forty lines back it.

Across every procedure, bundling into another procedure accounted for 3,117 denied lines at 30 practice groups in the same window — buildups are one of its largest homes. These are denied explanation-of-benefits lines ingested since 1 May 2026. Note what the second row is: at United Healthcare's Medicaid plans the buildup was not judged at all, it was never authorised, and that is a correction rather than an appeal.

What the carriers' own criteria say

Delta Dental publishes its buildup denial codes and, read as sentences rather than numbers, they sort themselves. From Core Buildup Dental Code: How to Avoid Claim Denials for Crowns, a Delta Dental provider article dated December 2022:

"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."

"5RX. We couldn't determine benefits because the submitted radiograph does not depict the entire tooth."

"570. We couldn't determine benefits because of missing preoperative periapical radiographic images."

"564. Submit a clinical treatment narrative."

Three of those say the carrier could not determine. One says the carrier determined. The same article gives the standard the tooth is measured against:

"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."

And it names the one case where a bundled buildup is recoverable after the fact — under an existing crown, where nobody could see the tooth until it came off:

"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. You'll need to submit additional documentation (intraoral images or x-rays taken once the crown is removed) to support payment of the buildup with the paid claim."

Aetna asks for something most offices never take. From Aetna Dental Clinical Policy Bulletin 043, Core Buildup, reviewed March 2025:

"Post-operative images with the core buildup in place depicting that the core buildup has been performed."

"Narratives may support the images, but not as a substitute for the required images nor will they serve as the sole determinate of coverage."

A letter cannot rescue an Aetna buildup claim that has no post-operative image. If the buildup is already under a seated crown, that image no longer exists.

Anthem contradicts the assumption most offices bill on. Anthem Dental Clinical Policy Guideline 02-901, Core Buildup — includes post and core procedures, published 1 January 2026:

"Endodontic treatment of an anterior tooth does not automatically constitute necessity for a core buildup or post and core."

"Core buildup and/or post and cores will not be considered when submitted for the purpose of pulp capping, insulation or protection of pulp, undercut block-outs, enhancement of box-form and fillers for reduction of final restorative material."

Delta Dental's guidance points the other way on the same question — it names dental history "such as following root canal treatment" as a reason a buildup may be allowed — so the habit that works at one carrier loses at the other.

Cigna publishes a same-day bundling rule with a named exception worth knowing, in Cigna Dental Coverage Determination Guidelines – DPPO, policy REST-06, 2026 edition:

"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."

A chairside-milled crown seated the same day is exactly the case Cigna says it will consider — and the office that mills its own crowns is the one most likely to be denied for it.

Principal sets a measurement, in Principal Dental Clinical Guidelines (form GP62410): a buildup is covered when there is "Breakdown of more than 50% of a tooth" and "Less than a 2-3 mm collar of sound tooth structure remaining at the gingival margin".

Why the split matters more than the carrier

Every carrier above is describing the same boundary in different words: is the material holding the crown on, or is it filling a hole in the preparation? The American Dental Association's own descriptor is what they all lean on, and Delta Dental quotes it directly — a buildup that "only involves a filler to eliminate an undercut, box form, or concave irregularity in the preparation" belongs to the crown prep.

That is why a bundling denial is rarely won by arguing. It is won, when it is won at all, by an image taken before the crown went on that shows how little tooth was left.

What to do

• Sort by wording, not by code. "Could not determine" is a missing document. "Included in the fee" is a decision.
• Photograph or radiograph the buildup in place, before the crown is seated. Aetna requires it outright, and it is the only evidence that survives the appointment.
• Send the pre-operative periapical showing the whole tooth, root tip included — the commonest reason a buildup claim is stalled rather than refused.
• Under an existing crown, capture the tooth once the crown is off. Delta Dental names that image as the route to payment on an already-paid claim.
• Do not assume a root canal carries the buildup on a front tooth. Anthem says outright that it does not.
• On a Medicaid plan, request the authorisation. A buildup refused for authorisation was never reviewed.

Related: why was my core buildup denied as included in the crown and when is a core buildup paid separately.

Numbers last refreshed September 2026.

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