Start New EnglishEspañol中文РусскийالعربيةTiếng ViệtFrançaisDeutsch한국어Tagalog Library Performance
BETA v.3.0

2025 CPT code 88366

In situ hybridization (e.g., FISH), per specimen; each multiplex probe stain procedure.

Refer to the most current CPT coding guidelines for surgical pathology.

Modifiers 26 (professional component) and TC (technical component) may be appended to 88366 depending on the portion of the service billed.

The medical necessity of 88366 is determined by the clinical indication for ISH testing.This might include diagnosing cancer, guiding treatment choices based on specific biomarkers, or assessing the risk of future disease. Documentation must support the clinical need for the test.

The lab analyst prepares slides and performs the technical aspects of the ISH test. The pathologist interprets the results, renders a diagnosis and prepares a report.

IMPORTANT:Use 88365 for initial single probe stain.Do not report 88365 and 88366 together for two probe stains that are part of a multiplex stain. For tumor ISH on cytology specimens (cellular material), use codes 88120-88121 instead.For ISH tests assessing conditions other than cancer (e.g., heritable diseases), use cytogenetics codes 88271-88275.Use codes 88271-88275 if a non-pathologist interprets the test.

In simple words: This lab test uses multiple special stains to look for specific genes in a tissue sample, like a tumor. A doctor then examines the stained sample under a microscope to help diagnose a medical condition.

This CPT code encompasses the in situ hybridization (ISH) procedure performed on a single patient specimen.The procedure involves applying a multiplex probe stain (multiple probes to detect multiple targets), followed by qualitative interpretation of stained slides by a pathologist to provide a pathologic diagnosis.The lab analyst performs the technical component (preparing stained slides), while the pathologist performs the professional component (interpretation and reporting).

Example 1: A patient presents with a suspicious breast mass. A biopsy is performed, and the tissue is sent for ISH testing using a multiplex probe to detect HER2, ER, and PR receptors. The results guide treatment decisions., A patient with a history of cervical dysplasia undergoes a colposcopy with biopsy.ISH is performed to evaluate for high-risk HPV types. The results are used to assess the risk of cervical cancer., A patient with bladder cancer undergoes a transurethral resection of a bladder tumor.The resected tissue is sent for ISH testing to evaluate for specific genetic markers that may influence prognosis and treatment selection.

** Code 88366 should be reported once per specimen regardless of the number of blocks or slides prepared.Always refer to the most up-to-date CPT manual for complete coding guidelines and updates.

** Only Enterprise users with EHR integration can access case-specific answers. Click here to request access.

Discover what matters.

iFrame™ AI's knowledge is aligned with and limited to the materials uploaded by users and should not be interpreted as medical, legal, or any other form of advice by iFrame™.