Summary & Overview
CPT 10021: Fine Needle Aspiration Biopsy, First Lesion
CPT code 10021 represents a fine needle aspiration (FNA) biopsy performed to obtain cells, a small tissue sample, or fluid from a cyst or palpable mass. Nationally, this code is used across outpatient settings and is important for early diagnostic workups that guide clinical management. The code is reported for the first lesion sampled and distinguishes FNA procedures from other biopsy techniques.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for FNA, common billing considerations, and national benchmarking information where available. The publication summarizes typical sites of service, common modifiers used with this procedure, and the relationship of 10021 to other biopsy codes in practice patterns.
This report is designed to inform clinical, coding, and policy stakeholders about the role of CPT code 10021 in diagnostic pathways, payer coverage patterns, and administrative considerations. Data not provided in the input are noted as unavailable, and readers will find guidance on which elements are commonly documented alongside the procedure in claims and medical records.
Billing Code Overview
CPT code 10021 describes a fine needle aspiration (FNA) biopsy performed by a provider to collect a small number of cells, a small amount of tissue, or fluid from a cyst or palpable mass. This code is reported for the first lesion biopsied when using a specialized needle and syringe for diagnostic sampling.
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Service type: Diagnostic needle biopsy (fine needle aspiration)
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Typical site of service: Outpatient clinic, physician office, ambulatory surgical center, or other outpatient procedural setting where small-needle aspiration of cysts or palpable masses is performed.
Clinical & Coding Specifications
Clinical Context
A 52-year-old patient presents to an outpatient dermatology clinic with a palpable 1.5 cm subcutaneous nodule on the right lateral neck that has persisted for several weeks. The clinician performs a 10021 fine needle aspiration (FNA) of the first palpable lesion to obtain cellular material for cytologic evaluation. The workflow includes focused history and consent, physical exam and site preparation, lesion localization by palpation (or ultrasound if needed), local anesthesia if indicated, insertion of a fine needle with aspiration to collect material, placement of aspirate onto slides and into fixative or transport media, and immediate labeling and documentation of the specimen and procedure. Specimen handling may include on-site assessment by cytology (ROSE) or sending to the laboratory for processing. The encounter is typically conducted in an ambulatory clinic, dermatology office, surgical office, or outpatient procedure suite and is billed as a diagnostic procedure for the first lesion biopsied using 10021.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
25 | Significant, separately identifiable Evaluation and Management service by the same physician on the same day of the procedure | Use when a distinct E/M visit is performed and documented on the same day as 10021. |