Summary & Overview
CPT 85385: Fibrinogen Antigen Assay, Laboratory Technical Service
CPT code 85385 represents the technical laboratory procedure to evaluate the presence of fibrinogen antigen in a patient specimen. This code captures the hands-on analytical steps performed by a laboratory analyst to detect fibrinogen protein components, an element relevant to coagulation assessment and bleeding or thrombotic disorder workups. Nationally, accurate coding of this laboratory service supports clinical decision-making, compliance with billing rules, and consistent claims adjudication across payers.
Key payers addressed in the coverage context include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication provides a concise overview of how CPT code 85385 is used in clinical workflows, the typical site of service (clinical or hospital laboratory), and common scenarios where fibrinogen antigen testing is ordered.
Readers will find benchmarks for typical billing and service line placement, a summary of payer coverage patterns (where available), and the clinical context that drives ordering of fibrinogen antigen assays. The report also flags where input data is limited and identifies areas labeled "Data not available in the input." This summary is intended for billing managers, laboratory directors, and policy analysts who need a clear national-level reference for CPT code 85385 and its role in laboratory diagnostic services.
Billing Code Overview
CPT code 85385 describes a laboratory technical service in which a lab analyst performs the procedural steps to evaluate the presence of fibrinogen antigen. This is a clinical laboratory diagnostic assay focused on detecting fibrinogen protein components in a patient specimen.
Service Type: Clinical laboratory test — fibrinogen antigen assay
Typical Site of Service: Clinical laboratory or hospital laboratory (in vitro diagnostic testing location)
Clinical & Coding Specifications
Clinical Context
A 58-year-old inpatient admitted for progressive shortness of breath and suspected disseminated intravascular coagulation (DIC) after sepsis. The treating physician orders a panel of coagulation studies, including a fibrinogen antigen assay, to evaluate clotting factor levels and guide transfusion and anticoagulation decisions. A phlebotomy technician collects a citrate-anticoagulated blood specimen and sends it to the clinical laboratory. In the lab, a medical laboratory scientist or technician performs the technical steps to measure fibrinogen antigen concentration using immunoassay techniques; this is documented in the laboratory information system and reported to the ordering clinician. The result may prompt additional testing (e.g., fibrinogen activity assays, D-dimer, platelet count) and influence management such as cryoprecipitate transfusion or adjustment of heparin therapy.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When reporting only the professional (interpretive) component by a physician for a lab test that has split technical/professional components. |
TC | Technical component | When reporting only the technical component performed by the laboratory or facility. |