CPT code 85009 identifies a manual white blood cell (WBC) count performed by a laboratory analyst using the buffy coat from a centrifuged blood specimen. This laboratory procedure is used when automated counts are unavailable, unreliable, or when microscopic review is clinically indicated. Nationally, the code matters for laboratory billing accuracy, clinical documentation, and appropriate coding of manual hematology services.

Key payers commonly involved include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the clinical context for CPT code 85009, the typical service setting, and the relevance of accurate reporting for payer reimbursement and claims processing. The publication also summarizes common modifiers used with laboratory services, national billing considerations, and where CPT code 85009 fits within hematology service lines.

This guidance is intended for a national audience of coding professionals, laboratory managers, and revenue cycle staff who need clarity on service definition, site-of-service expectations, and documentation elements that support billing for a manual WBC count using the buffy coat. Data not available in the input.