CPT code 99601 denotes a clinician home visit to provide an infusion or administer a specialty drug, covering up to the first two hours of the visit. This code matters nationally as home-based infusion and specialty drug administration expand care options outside traditional facilities, affecting access, care coordination, and payment pathways for high-cost therapies. Payers increasingly set specific coverage rules and documentation requirements for in-home infusion services, making clear code use important for billing accuracy and care continuity. Key payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the code's clinical context and site-of-service implications, an overview of typical payer coverage considerations, and what to expect in benchmarks and policy updates relevant to home-based infusion and specialty drug administration. The publication highlights how 99601 is used in practice, common documentation and billing considerations where available, and areas where payer policies commonly vary. Data not provided in the input for modifiers, associated taxonomies, specific ICD-10 diagnoses, and related codes is noted as unavailable.