Summary & Overview
CPT 80158: Cyclosporine Quantitative Assay, Laboratory Technical Component
CPT code 80158 represents the technical component of a quantitative laboratory assay to measure cyclosporine levels, an immunosuppressant used in transplant medicine and certain autoimmune disorders. Accurate measurement of cyclosporine is critical nationally for therapeutic drug monitoring to guide dosing, avoid toxicity, and maintain efficacy in patients on chronic immunosuppression. The code denotes the analytic work performed by laboratory personnel rather than specimen collection or interpretation.
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 cyclosporine monitoring, common sites where this service is provided, and the typical service characteristics tied to CPT code 80158. The publication outlines common billing modifiers and payer relevance where available and highlights what information is and is not present in the source input. This resource is intended to inform billing staff, laboratory managers, and policy analysts about the clinical and billing identity of CPT code 80158, relevant for national payer discussions, laboratory operations, and coding accuracy.
Billing Code Overview
CPT code 80158 describes a laboratory procedure in which a lab analyst performs the technical component of a quantitative assay to measure the concentration of cyclosporine, an immunosuppressant medication, in a patient specimen. This service is a therapeutic drug monitoring laboratory test performed to assess drug levels for dosing and safety.
Service type: Clinical laboratory — quantitative drug assay, technical component
Typical site of service: Clinical laboratory or hospital laboratory (specimen collected in outpatient clinic, hospital, or reference lab and analyzed in the lab)
Clinical & Coding Specifications
Clinical Context
A typical patient is a 45–65-year-old solid organ transplant recipient (e.g., kidney or liver transplant) receiving lifelong immunosuppression with cyclosporine. During routine post-transplant monitoring or when signs of rejection, toxicity, or altered drug interactions occur, the clinician orders therapeutic drug monitoring to quantitate trough or random cyclosporine levels. A phlebotomist obtains a blood specimen per laboratory protocol (timing noted, often a pre-dose trough), the specimen is sent to the clinical laboratory, and a lab analyst performs a quantitative assay of cyclosporine using immunoassay or mass spectrometry. Results are reported to the transplant team and used to adjust dosing to maintain therapeutic levels and minimize rejection or nephrotoxicity. Typical site of service is an outpatient hospital laboratory, independent clinical laboratory, or hospital inpatient lab when monitoring hospitalized transplant patients. Service type: quantitative therapeutic drug monitoring (laboratory analytical service).
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing for only the professional (interpretive) component of a test if applicable and reportable separately. |
TC |