Summary & Overview

CPT 85415: Fibrinolytic Factor/Inhibitor Assay

CPT code 85415 represents a laboratory assay for a fibrinolytic factor or inhibitor related to plasminogen activation. This test assesses key regulators of plasmin generation and fibrinolysis, informing diagnosis and management of bleeding and thrombotic conditions. The code is relevant across inpatient and outpatient laboratory settings and is commonly ordered when evaluating unexplained bleeding, suspected hyperfibrinolysis, or monitoring certain therapeutic interventions.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of how CPT code 85415 is defined clinically, typical sites of service, and common contexts for ordering the test. The publication summarizes national coding and billing considerations, reimbursement benchmarks where available, and clinical implications for lab operations and provider documentation.

This summary is intended to provide clinicians, laboratory managers, and billing professionals with a clear, national-level reference for CPT code 85415, including what the code represents, why it matters in patient care, and the main topics covered in the full publication: coding guidance, payer coverage patterns, and clinical context for test utilization. Data not available in the input will be noted where applicable.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicareCPT 85415fibrinolysiscoagulation testinglaboratory assayplasminogen activationclinical laboratorymedical billingdiagnostic testing

Billing Code Overview

CPT code 85415 describes a laboratory test performed by a lab analyst to measure a fibrinolytic factor or inhibitor related to plasminogen activation. This assay evaluates components of the fibrinolytic system that regulate plasmin generation and activity, which are relevant to bleeding, clotting, and thrombotic disorders.

Service Type: Clinical laboratory assay — coagulation/fibrinolysis testing

Typical Site of Service: Clinical laboratory or hospital laboratory

Clinical & Coding Specifications

Clinical Context

A 58-year-old woman with a history of recurrent venous thromboembolism is evaluated for an unexplained bleeding episode and abnormal coagulation screening. The hematology clinic orders specialized fibrinolytic testing to evaluate components of plasminogen activation (for example plasminogen activity, plasmin inhibitor levels, or tissue plasminogen activator/plasminogen activator inhibitor balance). A blood specimen is collected in a properly labeled citrate tube and sent to the clinical laboratory. The laboratory analyst performs the assay designated by 85415 to measure a fibrinolytic factor or inhibitor related to plasminogen activation. Results are reported in the laboratory information system and routed to the ordering hematologist. Typical sites of service include hospital clinical laboratories, independent reference laboratories, and hospital outpatient laboratories. The clinical workflow includes specimen collection, accessioning, assay performance by a trained laboratory scientist, quality control verification, result validation by a laboratorian or pathologist, and transmission of results to the ordering clinician for diagnostic and treatment decision-making.

Coding Specifications

Modifier	Description	When to Use
`26`	Professional component	Use when billing only the professional (interpretation/reading) component if separated from the technical service.
`TC`	Technical component	Use when billing only the technical component (laboratory testing and materials) without the professional component.
`59`	Distinct procedural service	Use when the fibrinolytic assay is distinct and separate from another service performed on the same day and medical necessity supports separate billing.
`90`	Reference (outside) laboratory	Use when the specimen is sent to an outside reference laboratory for testing.
`91`	Repeat clinical diagnostic laboratory test	Use when the same laboratory test is repeated on the same date to obtain subsequent results (not for quality control).
`52`	Reduced services	Use when the test is partially reduced or not performed to its full extent and reduced services are documented.
`53`	Discontinued procedure	Use if testing was started but discontinued and appropriately documented.
`22`	Increased procedural services	Use when work required to perform the test is substantially greater than typically required and documentation supports additional resource use.
`90`	Reference (outside) laboratory	Use when testing is performed by an outside laboratory (listed to show common relevance).
`QK`	CLIA-waived or moderate complexity personnel?	Use for Medicare when specific staffing/payment rules for lab testing are applicable (use only when payer-specific rules require these Q modifiers).

Taxonomy Code	Specialty	Notes
207RH0000X	Hematology	Physicians who interpret complex coagulation and fibrinolysis testing and manage related disorders.
363L00000X	Clinical Laboratory	Laboratory directors and pathologists overseeing specialized coagulation assays.
1945R0202X	Pathology	Clinical pathologists who validate and sign out specialized coagulation test results.
207RH0000X	Internal Medicine - Hematology (subspecialty overlap)	Hospital-based internists with hematology focus coordinating testing and treatment.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`D68.9`	Coagulation defect, unspecified	General indication for specialized coagulation and fibrinolytic factor testing when a specific disorder is not yet identified.
`I82.409`	Acute embolism and thrombosis of unspecified deep veins of unspecified lower extremity	Thrombotic events prompt evaluation of fibrinolytic system components when recurrent or unexplained.
`I26.99`	Other pulmonary embolism without acute cor pulmonale	Pulmonary embolism cases may lead to evaluation of plasminogen activation pathways in recurrent or atypical presentations.
`D66`	Hereditary factor VIII deficiency (Hemophilia A)	While primarily a coagulation factor deficiency, fibrinolytic testing can be relevant in complex bleeding presentations.
`D67`	Hereditary factor IX deficiency (Hemophilia B)	Similar relevance in complex bleeding workups where fibrinolysis may contribute to phenotype.
`R58`	Hemorrhage, not elsewhere classified	Unexplained bleeding often triggers advanced coagulation and fibrinolytic testing.
`D68.51`	von Willebrand disease	Coagulation disorder where additional fibrinolytic testing may be ordered if bleeding is disproportionate to usual laboratory findings.
`T81.89XA`	Other complications of procedures, initial encounter	Post-procedural bleeding complications may prompt fibrinolytic factor or inhibitor testing to evaluate abnormal fibrinolysis.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`85305`	Prothrombin time (PT) and partial thromboplastin time (PTT) tests	Common baseline coagulation tests ordered before or alongside fibrinolytic factor testing to assess overall coagulation status.
`85610`	Prothrombin time, INR reporting	Often performed in the workup of bleeding or thrombotic disorders and to monitor anticoagulant therapy when interpreting fibrinolytic testing.
`85320`	Platelet function studies (e.g., bleeding time alternatives)	May be ordered when platelet-related bleeding disorders need exclusion alongside fibrinolytic factor assays.
`86140`	Fibrinogen assay (quantitative)	Directly related to fibrinolysis evaluation; fibrinogen levels provide context for plasminogen activation testing.
`85730`	Antibody detection (coagulation)	May be performed when inhibitor-mediated fibrinolytic dysfunction is suspected and to identify specific inhibitors.