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.