Summary & Overview
CPT 85635: Reptilase Clotting Time Assay
CPT code 85635 denotes a laboratory coagulation assay measuring the impact of Reptilase on clotting time. The test is a specialized hemostasis study that helps differentiate fibrinogen and fibrin polymerization pathways and can clarify coagulopathy diagnoses when thrombin-based assays are inconclusive. Nationally, this code represents a niche but clinically relevant diagnostic service used by hospitals and reference laboratories to support hematology and perioperative care.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication outlines expected clinical contexts for the test, typical sites of service, and payer coverage considerations where available.
Readers will learn the clinical purpose of the assay, where the service is commonly performed, and practical billing metadata associated with CPT code 85635. Benchmarking details, reimbursement context, and payer coverage patterns are discussed when available. Data not provided in the input (such as associated taxonomies, ICD-10 diagnoses, related codes, and detailed payer-specific policies) are noted as not available.
Billing Code Overview
CPT code 85635 describes a laboratory assay in which a lab analyst measures the effect of Reptilase on blood clotting time. This test evaluates how Reptilase, a snake-derived enzyme, influences fibrin formation and is used to assess coagulation pathways distinct from thrombin-based assays.
Service type: Laboratory diagnostic test — coagulation study
Typical site of service: Clinical laboratory or hospital laboratory
Clinical & Coding Specifications
Clinical Context
A typical patient is a hospitalized adult or outpatient referred for hemostasis testing after an unexplained abnormal bleeding screen, prolonged clotting times, or monitoring of anticoagulant/antiplatelet therapy where Reptilase is used to differentiate fibrinogen abnormalities from heparin effect. A patient scenario: a 58-year-old male presents with prolonged bleeding after central line placement and an elevated thrombin time; the clinician requests a Reptilase time to assess whether heparin contamination or dysfibrinogenemia is present. Blood is drawn to the laboratory; the lab analyst performs the 85635 Reptilase time assay using plasma, documents the specimen, runs controls, interprets clotting time relative to reference ranges, and reports results to the ordering clinician. Typical sites of service include hospital inpatient laboratory, hospital outpatient laboratory, and independent clinical diagnostic laboratories. Turnaround time varies from stat (emergent peri‑procedural bleeding) to routine outpatient processing.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation component if separate from technical services. |
TC |