HCPCS Level II code S3630 represents a direct eosinophil count performed on peripheral blood. Eosinophil counts are clinically important for diagnosing and monitoring allergic conditions, parasitic infections, and certain hematologic disorders, making this laboratory measurement widely used across ambulatory and hospital settings. Nationally, standardized reporting and accurate coding for hematology tests support appropriate clinical decision-making and claims processing.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of coding context, common billing practices, and payer coverage considerations. The publication outlines clinical context for use of eosinophil counts, typical sites of service, and available benchmarking where provided. Where input data is incomplete, the document notes that additional payer-specific coverage rules and payment rates must be consulted directly with each insurer for definitive guidance.

This summary equips billing professionals, clinical laboratorians, and policy analysts with a concise reference to the purpose of S3630, the clinical scenarios in which a direct eosinophil count is ordered, and the types of payer policies and claims processes that commonly apply to hematology laboratory services.