Summary & Overview
CPT 86360: CD4 and CD8 Cell Counts with CD4:CD8 Ratio
CPT code 86360 denotes a laboratory immunology assay that measures CD4 and CD8 T‑lymphocyte counts and computes the CD4:CD8 ratio. Nationally, this test is central to monitoring cellular immune function in people with HIV and can inform clinical staging and management decisions. It is performed routinely in outpatient clinics, hospital order sets, and standalone clinical laboratories.
Key payers addressed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the clinical context for ordering the test, typical sites of service, payer coverage landscape, and where this code sits in laboratory service lines. The publication outlines benchmarking points and common billing considerations relevant to laboratories and clinicians, and highlights policy and coding updates that affect claims submission and reimbursement workflows.
This summary is intended for laboratory managers, billing professionals, and clinical leaders seeking a national overview of CPT code 86360, its clinical purpose, and the payer environment that influences billing and payment for CD4/CD8 testing.
Billing Code Overview
CPT code 86360 describes a laboratory immunology test that measures CD4 and CD8 lymphocyte counts in a blood specimen and calculates the CD4:CD8 ratio. The test quantifies two major T‑lymphocyte subsets used to assess cellular immune status, commonly ordered after diagnosis of HIV infection to monitor immune competence.
Service type: Laboratory immunology assay
Typical site of service: Clinical laboratory or hospital laboratory (blood specimen)
Clinical & Coding Specifications
Clinical Context
A 34-year-old patient with newly diagnosed HIV infection presents for baseline immune status assessment. The clinician orders a quantitative lymphocyte subset panel to measure CD4 and CD8 T‑lymphocyte counts and the CD4/CD8 ratio to guide initial staging and antiretroviral therapy planning. A phlebotomy technician draws a peripheral blood specimen in an outpatient laboratory or hospital clinical laboratory. The specimen is processed by flow cytometry in the clinical immunology or hematology lab; the lab analyst performs enumeration of CD4 and CD8 cells and calculates the CD4:CD8 ratio. Results are reported to the ordering provider via the electronic health record; values are used for disease staging, prophylaxis decisions (e.g., opportunistic infection prophylaxis thresholds), and ongoing monitoring during therapy. Typical sites of service include outpatient clinic laboratories, reference laboratories, hospital clinical laboratories, and community phlebotomy centers.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing only the professional interpretation or reporting component if the lab sends interpretation separately. |
90 | Reference (outside) laboratory |