Summary & Overview
CPT 85293: High Molecular Weight Kininogen (Fitzgerald Factor) Clotting Test
CPT code 85293 represents a specialized coagulation laboratory test that identifies the presence of high molecular weight kininogen (Fitzgerald factor) in patient plasma. This assay is clinically relevant for investigating rare intrinsic pathway abnormalities and unexplained bleeding or thrombotic tendencies. As a niche hematology test, it is typically performed in hospital or reference clinical laboratories and may inform downstream diagnostic and management decisions.
Key payers in a national analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find benchmarks and payer coverage patterns for utilization of specialized coagulation assays, a clinical context for when 85293 is ordered, and practical notes on typical sites of service and service type. The publication also summarizes common billing modifiers used with laboratory services and highlights where data is not available in the input.
The content is intended for billing managers, laboratory directors, and policy analysts seeking a concise reference on the clinical purpose and payer landscape for CPT code 85293, plus what to expect in terms of reporting and typical service settings.
Billing Code Overview
CPT code 85293 describes a laboratory clotting assay performed to detect high molecular weight kininogen (Fitzgerald factor) in a patient’s plasma. The test is a specialized hematology/coagulation procedure used to evaluate components of the intrinsic coagulation pathway and investigate unexplained clotting abnormalities.
Service Type: Specialty coagulation laboratory test
Typical Site of Service: Clinical laboratory or hospital laboratory
Clinical & Coding Specifications
Clinical Context
A 42-year-old patient with a history of recurrent unexplained angioedema and prolonged coagulation screening is referred to the hematology laboratory to evaluate contact system components. The clinician orders a specialized clotting assay to detect high molecular weight kininogen (Fitzgerald factor) deficiency or dysfunction. A phlebotomy sample of citrated plasma is collected in the outpatient laboratory (typical site: hospital outpatient lab or independent clinical laboratory). The lab analyst performs 85293 using an activated partial thromboplastin time (aPTT)-based or specific clotting assay protocol to determine presence or absence of high molecular weight kininogen. Results are documented in the laboratory information system and reported to the ordering hematologist or allergist; interpretation may prompt additional testing for prekallikrein, factor XII, or hereditary angioedema panels and influence clinical management such as targeted genetic testing or specialist referral.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier applicable | Rarely used; indicates no specific modifier applies when billing systems require a placeholder |
11 |