Summary & Overview
CPT 85245: Platelet Aggregation with Ristocetin for vWF/Factor VIII Evaluation
CPT code 85245 denotes a laboratory platelet aggregation test using ristocetin to evaluate coagulation factor VIII and von Willebrand factor function from patient plasma. This specialized diagnostic assay is clinically significant for identifying von Willebrand disease and platelet function defects that affect primary hemostasis. Nationally, precise coding of 85245 supports appropriate laboratory reporting, claims processing, and clinical interpretation for disorders of platelet–von Willebrand factor interaction.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical purpose and typical service setting for 85245, along with benchmark and policy context where available. The publication outlines common billing considerations, payer coverage patterns, and how 85245 fits into diagnostic workflows for bleeding disorders.
The report is intended to inform coding staff, laboratory managers, and policy analysts about the clinical role of the test, typical sites of service, and the payer landscape. Data not available in the input are noted explicitly where applicable.
Billing Code Overview
CPT code 85245 describes a platelet aggregation test using ristocetin performed by a laboratory analyst to evaluate coagulation factor VIII / von Willebrand factor function using patient plasma. This is a specialized diagnostic coagulation assay used to assess platelet-von Willebrand factor interactions and support diagnosis of von Willebrand disease and related hemostatic disorders.
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Service type: Laboratory diagnostic assay (platelet function testing)
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Typical site of service: Clinical laboratory or hospital laboratory setting
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Clinical & Coding Specifications
Clinical Context
A 28-year-old woman with a history of mucocutaneous bleeding and prolonged mucosal bleeding after dental extraction is evaluated in a hematology clinic. Preliminary laboratory tests show a prolonged bleeding time and reduced von Willebrand factor antigen on initial screening. The hematologist orders specialized platelet function testing, including a ristocetin-induced platelet aggregation study, to assess platelet–von Willebrand factor interaction and to help distinguish von Willebrand disease subtypes or platelet-type von Willebrand disease.
Specimen collection is venous plasma drawn into appropriate anticoagulant tubes and processed by the clinical laboratory. The laboratory analyst performs 85245 (platelet aggregation with ristocetin) using patient platelet-rich plasma and ristocetin reagent, recording aggregation responses at multiple concentrations. Results are reviewed by the hematology team to correlate with antigen and activity assays (e.g., VWF antigen, VWF activity, and factor VIII levels) and the patient’s clinical history to guide diagnosis and management planning. Typical sites of service include hospital outpatient laboratories, reference laboratories, and specialized coagulation/hematology laboratories in tertiary centers.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation/performance portion if separate from the facility/lab technical component. |