CPT code 86361 represents an absolute CD4 cell count, a laboratory test that quantifies CD4 T-lymphocytes per microliter of blood to assess immune function in patients with HIV infection. Nationally, this test is a key clinical marker used for staging disease, guiding antiretroviral therapy decisions, and monitoring immune recovery or decline. Payer coverage and payment policies for CD4 testing influence access to timely monitoring and follow-up care for people living with HIV.

Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise review of clinical context for CD4 testing, typical sites of service where the test is performed, and the common modifiers associated with laboratory billing. The publication summarizes benchmark considerations and highlights policy and coverage elements that commonly affect reimbursement and utilization for laboratory services nationally.

This summary provides clinicians, laboratory managers, and policy analysts with a focused overview of CPT code 86361, what it measures, why it matters for patient management, and the types of payer policies that typically apply. Data not available in the input are noted where relevant in detailed sections.