D3421 is the CDT code for an apicoectomy on a premolar, first root. An apicoectomy is the surgical removal of the root tip and the infected tissue around it, usually after conventional root canal therapy has not resolved the problem. D3421 is the premolar code, which separates it from D3410 for anterior teeth and D3425 for molars.
Last updated June 2026 · Reviewed by the PracticeAlpha billing team
Get help with D3421 claims →Use D3421 when performing an apicoectomy on a premolar. The procedure surgically removes the root tip and the surrounding periapical pathology, typically when conventional root canal therapy or retreatment has not resolved persistent infection. D3421 reports the first root treated on the premolar.
Common clinical scenarios: A premolar with persistent periapical pathology after root canal therapy. A premolar where retreatment is not feasible and surgery is the next step. A premolar with a periapical lesion that requires surgical access to the root end.
Do NOT use D3421 for: An anterior tooth (use D3410). A molar (use D3425). Each additional root beyond the first on the same tooth (use D3426). A retrograde filling, which is reported separately with D3430.
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Surgical removal of the root tip on a premolar, first root. Used for persistent periapical pathology on a bicuspid after conventional treatment.
The same surgical procedure on an anterior tooth. Same approach, different tooth type. Anterior teeth are coded with D3410, not D3421.
Billing tip: Apicoectomy codes are split by tooth type. Anterior is D3410, premolar is D3421, molar is D3425. Confirm the tooth number matches the code so the position is consistent on the claim.
D3421 is the premolar code. Using it on an anterior tooth or a molar is a position mismatch. Anterior is D3410 and molar is D3425. When the tooth number does not match the code, payers flag the inconsistency and deny the claim. Confirm the tooth type before selecting the code.
Endodontic surgery requires imaging that shows the periapical pathology. Without a radiograph demonstrating the lesion and the root end, the payer cannot see why surgery was needed. Include preoperative imaging that supports the diagnosis and the surgical approach.
An apicoectomy usually follows prior root canal therapy that did not resolve the problem. If the record does not show the endodontic history and persistent pathology, the payer may question the necessity of surgery. Document the prior treatment and why surgery was indicated.
Surgical claims need an operative note describing the procedure. The note should describe the flap, the root end resection, and the management of the periapical tissue. Thin documentation that does not describe the surgery can lead to denials.
Record the specific premolar treated. The tooth number must correspond to a premolar so the code and position are consistent.
Include imaging that shows the periapical pathology and the root end. This is the primary justification for the surgery.
Document the prior root canal therapy and the persistent pathology that made the apicoectomy necessary.
Describe the surgical procedure, including flap reflection, root end resection, and management of the periapical tissue.
Note any additional roots treated, reported with D3426, and any retrograde filling, reported separately with D3430, so each procedure is captured correctly.
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Learn about our billing servicesD3421 is the CDT code for an apicoectomy on a premolar, first root. An apicoectomy is the surgical removal of the root tip and surrounding infected tissue. D3421 covers the first root treated on a premolar tooth.
D3410 is an apicoectomy on an anterior tooth. D3421 is an apicoectomy on a premolar. The codes are separated by tooth type, so the position of the tooth determines which apicoectomy code applies.
D3421 is an apicoectomy on a premolar, while D3425 is an apicoectomy on a molar. Both report the first root of their respective tooth type. The tooth type, premolar versus molar, decides the code.
D3421 covers the first root of a premolar. Premolars usually have one root, but when an additional root is treated surgically on the same tooth, the additional root is reported with D3426, apicoectomy, each additional root.
Not necessarily. A retrograde filling placed at the resected root end is reported separately with D3430, retrograde filling, per root. Verify whether the filling is included in the surgical visit or reported in addition based on the procedures performed.
Common reasons include a tooth type mismatch, such as using the premolar code for a molar, missing radiographs showing the periapical pathology, no documented prior root canal, frequency rules, and incomplete operative notes for the surgery.
Search all 206 CDT codes in our dental coding guide.