Summary & Overview
CPT 85576: Platelet Aggregation Study, Platelet Function
CPT code 85576 represents a laboratory platelet aggregation test in which a lab analyst evaluates platelet clumping after adding an agent to a blood specimen. This assay is used to diagnose or evaluate platelet function disorders and inform clinical management of bleeding or thrombotic risk. Nationally, platelet function testing plays a role in hematology, preoperative assessment, and in managing patients on antiplatelet therapies.
Major payers in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context for 85576, typical sites of service, common billing considerations, and a summary of payer coverage patterns where available. The publication also outlines benchmarks for utilization and reimbursement, identifies relevant modifiers and coding nuances, and summarizes policy updates affecting laboratory billing for platelet function studies.
This summary is written for a national audience and aims to help billing professionals, clinical laboratorians, and policy analysts quickly understand what CPT code 85576 covers, why it matters in clinical practice, and where to look for payer-specific guidance. Data not available in the input is noted where applicable in detailed sections.
Billing Code Overview
CPT code 85576 describes a laboratory procedure in which a laboratory analyst evaluates platelet aggregation (clumping) after adding an agent to a blood specimen. This test assesses how platelets respond to specific agonists and helps identify disorders of platelet function that can contribute to bleeding or thrombotic risks.
Service type: Diagnostic laboratory test — platelet function/aggregation study
Typical site of service: Hospital laboratory, independent clinical laboratory, or hospital outpatient laboratory
Clinical & Coding Specifications
Clinical Context
A 55-year-old outpatient with unexplained mucocutaneous bleeding and a history of antiplatelet medication use presents to the hematology clinic. The clinician suspects an acquired platelet function defect or drug-induced platelet dysfunction and orders platelet aggregation testing to assess platelet clumping in response to agonists. The patient arrives at the hospital laboratory or an outpatient phlebotomy suite for venipuncture; citrated whole blood is collected and promptly transported to the coagulation/hematology laboratory. A technologist prepares platelet-rich plasma and performs the aggregation assay by adding specific agonists (for example, ADP, collagen, epinephrine) while measuring changes in light transmission or aggregometry tracings. Results are reported to the ordering hematologist or primary care provider; abnormal aggregation patterns guide further evaluation (drug effects, inherited platelet function disorders, von Willebrand disease subtypes) and management planning. Typical sites of service include hospital outpatient laboratories, independent clinical laboratories, and specialty hematology clinics with on-site lab capability.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing only the professional interpretation component if instrumentation is billed separately |
59 |