Summary & Overview
CPT 3494F: CD4+ Cell Count <200 cells/µL
CPT code 3494F denotes a CD4+ cell count result below 200 cells/µL, a clinically important marker of advanced immune suppression in people living with HIV. Nationally, documentation of CD4 counts at this threshold influences clinical staging, opportunistic infection risk assessment, and eligibility for certain services and supports. Payers use such result codes to track quality measures, population health management, and care coordination for individuals with HIV.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the code’s clinical context, typical sites of service, and how the code is used in administrative and quality-reporting workflows. The publication summarizes available benchmarks and policy considerations relevant to laboratory reporting and quality measurement, highlights implications for care management programs, and outlines common clinical interpretations tied to a CD4+ count under 200 cells/µL.
This summary is intended for national audiences including clinicians, coding professionals, payer policy teams, and health system administrators who need concise context on CPT code 3494F and its role in HIV care monitoring and quality reporting.
Billing Code Overview
CPT code 3494F documents a CD4+ (cluster of differentiation 4) cell count of less than 200 cells per microliter. This result indicates a substantially reduced CD4+ T‑lymphocyte level and is used to assess immune function in people living with human immunodeficiency virus (HIV).
Service type: Laboratory test — CD4+ cell count (low result reporting)
Typical site of service: Clinical laboratory or outpatient phlebotomy setting, including hospital outpatient labs and standalone reference laboratories. Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A typical patient is a person living with human immunodeficiency virus (HIV) presenting for routine outpatient laboratory monitoring or evaluation of new/ongoing opportunistic infections. The patient may be established in an infectious disease clinic, HIV primary care clinic, or a community health center. Clinical workflow: the provider orders a 3494F CD4+ lymphocyte count as part of baseline HIV staging, periodic monitoring of immune status after antiretroviral therapy (ART) initiation or change, or when symptoms suggest immunosuppression. A phlebotomy technician draws a venous blood specimen, labels it with the patient and order information, and sends it to the clinical laboratory. The laboratory performs flow cytometry or an equivalent validated method to quantify CD4+ cells per microliter and reports the numeric result. The provider documents the CD4+ cell count value (<200 cells/µL for 3494F), interprets immune status relative to opportunistic infection risk, and records management decisions in the medical record. Typical site of service: outpatient clinic, hospital outpatient lab, community health center, or inpatient ward when monitoring hospitalized patients. Service type: diagnostic laboratory test (hematology/immunophenotyping). Typical patient scenario: an HIV-positive adult with a recent ART change whose CD4+ count returned as less than 200 cells/µL, prompting counseling about opportunistic infection prophylaxis and closer follow-up.
Coding Specifications
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