CPT Code 10021: Fine Needle Aspiration (FNA) Biopsy, Without Imaging Guidance

Learn more about the CPT code 10021, a fine needle aspiration (FNA) code, and its billing guidelines and documentation requirements.

Use Code

What is the 10021 CPT code?

CPT code 10021, maintained by the American Medical Association, is reported for fine needle aspiration biopsy performed without imaging guidance.

It is used to sample cellular material from a palpable breast mass, suspicious lymph nodule, or cyst (for the same breast, if applicable) for cytologic examination. Common anatomical sites include the thyroid, lymph nodes, and breast.

CPT code 10021 documentation requirements

Ensure accurate documentation by including the following in the patient's medical records:

Indication for FNA (e.g., palpable nodule, cyst)
Site and laterality of aspiration
Number of passes made
Type of specimen obtained (fluid, cytologic material)
Description of technique (needle gauge, aspiration method)
Complications during or immediately after the procedure
Post-procedure instructions and monitoring for complications

It is important to include a pathology/lab reference if the specimen is sent out.

CPT code 10021 billing guidelines

For accurate medical billing and reimbursement, the healthcare provider using the code must follow the guidelines below:

Report for only the first lesion aspirated without imaging guidance.
Do not bill with imaging guidance codes like 76942, 77001, etc.
If aspiration converts to core biopsy, document separately and consider reporting appropriate biopsy codes.

Use modifiers for aspiration of multiple distinct palpable lesions during the same session.

Other relevant CPT codes

10005: FNA with ultrasound guidance
10006: FNA biopsy procedures for additional lesions when ultrasound guidance is used
10007–10008: FNA with fluoroscopic guidance

Frequently asked questions

No, CPT code 10021 is reported once per separately identifiable lesion, regardless of the number of needle passes performed during the procedure. According to CMS guidelines, the unit of service for fine needle aspiration biopsy codes (including 10021) is the lesion itself, not the number of passes or specimens obtained.

If imaging guidance was used during the fine needle aspiration procedure but not documented in the medical record, CPT code 10021 should not be reported. Accurate coding requires clear documentation of whether imaging guidance was utilized; if imaging was employed, the appropriate imaging-guided FNA codes (such as 10005 for ultrasound guidance) must be reported instead to ensure compliance and proper reimbursement.

Yes, local anesthesia is considered an integral part of the fine needle aspiration procedure and is included in CPT code 10021. It should not be reported separately, as the use of local anesthesia is bundled into the procedure code and does not warrant additional billing.