HCPCS Level II code G0398 represents an unattended home sleep study using a Type II portable monitor that records a minimum of seven physiologic channels, including EEG, EOG, EMG, ECG/heart rate, airflow, respiratory effort, and oxygen saturation. This testing modality enables comprehensive sleep physiology assessment outside the sleep laboratory, supporting diagnosis and management of sleep-disordered breathing and other sleep disorders at scale. Nationally, home sleep testing using Type II devices is important for increasing access to diagnostic sleep services and reducing reliance on in-lab polysomnography for populations who can be safely evaluated at home.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and the Medicare program. Readers will find a concise overview of the clinical service captured by G0398, how it differs from other ambulatory and in-lab sleep testing codes, and the policy and billing considerations that affect utilization and coverage. The publication outlines typical sites of service, common billing modifiers (listed separately), and where to find related coding references. It also highlights benchmarks and policy updates affecting home sleep testing reimbursement and documentation practices. Data not available in the input for some fields is noted where applicable.