Summary & Overview
CPT 85555: Osmotic Fragility Test for Red Blood Cell Hemolysis
CPT code 85555 represents a specialized clinical laboratory test that assesses immediate osmotic fragility of red blood cells, measuring the degree of hemolysis when RBCs are subjected to hypotonic stress. This assay is used in diagnostic evaluation of hemolytic anemia and related red cell membrane or osmotic stability disorders and is relevant to laboratories, clinicians, and payers because results can guide further diagnostic workups and management.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a national-level overview of clinical context for the test, expected service setting, and payer coverage considerations. The publication summarizes reimbursement benchmarks where available, common billing and coding considerations, and the clinical scenarios that typically prompt ordering of the test.
The report provides practical information for coding and billing teams, laboratory administrators, and policy analysts: it outlines what the code represents, typical sites of service, payer coverage landscape, and areas where policy updates or billing nuances commonly arise. Data not available in the input will be identified as such.
Billing Code Overview
CPT code 85555 describes a laboratory assay in which a lab analyst evaluates the degree of hemolysis of red blood cells (RBCs) under immediate osmotic stress. The test measures how RBCs respond when exposed to a hypotonic environment to determine susceptibility to hemolysis.
Service Type: Clinical laboratory diagnostic test
Typical Site of Service: Clinical laboratory or hospital laboratory
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Clinical & Coding Specifications
Clinical Context
A typical patient is an adult or pediatric patient referred from hematology or a primary care provider for laboratory evaluation of suspected red blood cell membrane or hemoglobinopathy-related fragility. The patient presents with symptoms such as chronic hemolytic anemia, unexplained jaundice, elevated reticulocyte count, dark urine, fatigue, or a history of neonatal hyperbilirubinemia. The clinical workflow begins with a phlebotomy draw of whole blood into an appropriate anticoagulated tube and transport to the clinical laboratory. A laboratory analyst performs the osmotic fragility test (85555) by exposing red blood cells to serial hypotonic saline solutions and observing hemolysis endpoints. Results are reported to the ordering clinician and incorporated into the diagnostic evaluation for conditions such as hereditary spherocytosis, elliptocytosis, thalassemia trait, autoimmune hemolytic anemia (as a complementary test), and for confirmation of suspected RBC membrane defects. The test is typically ordered by hematologists, pediatricians, or internists and performed in hospital-based, reference, or outpatient clinical laboratories with appropriate quality-control procedures and reporting of interpretive comments.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when the physician interprets and reports the test result separately from the technical performance of the laboratory analysis. |