CPT code 88140 designates a laboratory test in which a trained analyst examines a peripheral blood smear to identify polymorphonuclear "drumstick" nuclear protrusions for sex chromatin (Barr body) identification. This microscopic technical service supports clinical and forensic determinations of chromatin patterns and can inform downstream genetic or diagnostic workflows. Nationally, the code matters because it defines billing for a specialized morphologic laboratory procedure that has implications for clinical documentation, lab capacity, and reimbursement consistency across payers.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise explanation of the clinical context for the test, typical sites of service, and the service type captured by the code. The publication also outlines common billing modifiers (provided separately), and highlights areas where data was provided versus where input was not available.

This summary equips laboratory managers, clinical billers, and policy analysts with a clear, national-level reference for CPT code 88140, including what the code represents, why it is used, and what to expect in terms of clinical application and billing classification. Data not available in the input.