Summary & Overview
CPT 85705: Tissue Thromboplastin Inhibition Test for Lupus Anticoagulant
Headline: CPT code 85705: Tissue Thromboplastin Inhibition Test for Lupus Anticoagulant
Lead: CPT code 85705 denotes the tissue thromboplastin inhibition test (TTI), a plasma-based laboratory assay used to detect lupus anticoagulant inhibitors—autoantibodies that can drive pathologic clot formation. The test is clinically significant for evaluating patients with unexplained thrombosis or recurrent pregnancy loss and for guiding anticoagulation management decisions.
CPT code 85705 represents a specialized coagulation/immunology laboratory service with national relevance due to rising attention to thrombotic disorders and autoimmune contributors to clot risk. Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical context for the assay, typical sites of service, common billing modifiers, and payer considerations where available. The report outlines benchmark considerations, coding context, and policy update highlights relevant to laboratory administrators and billing staff.
This summary provides a concise reference to the test purpose, expected clinical scenarios prompting the assay, and what to expect when coding and billing CPT code 85705 across major national payers. Data not available in the input is noted where applicable.
Billing Code Overview
CPT code 85705 describes a tissue thromboplastin inhibition test (TTI) performed on plasma to detect lupus anticoagulant inhibitors, autoantibodies associated with increased risk of thrombosis. The procedure identifies inhibitors that interfere with tissue thromboplastin activity and assists in diagnosing antiphospholipid antibody-related clotting disorders.
Service Type: Laboratory - Coagulation/Immunology Test
Typical Site of Service: Clinical laboratory or hospital laboratory (ambulatory and inpatient specimen processing)
Clinical & Coding Specifications
Clinical Context
A 42-year-old female with a history of recurrent unexplained venous thromboembolism and prolonged clotting times on routine coagulation screening is referred to the hospital laboratory for specialized antiphospholipid testing. The clinician suspends anticoagulation when medically safe and orders a tissue thromboplastin inhibition test to detect lupus anticoagulant (LA) inhibitors. A phlebotomy encounter occurs in the outpatient laboratory; the specimen is processed by the hematology coagulation laboratory. The lab analyst performs 85705 (tissue thromboplastin inhibition test) using patient plasma, runs appropriate controls and mixing studies, documents results, and reports presence or absence of LA inhibitors to the ordering clinician for correlation with clinical history and other antiphospholipid tests.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
11 | Normal or usual service | When 85705 is performed as described without unusual effort or service-level changes |
22 | Increased procedural services |