Summary & Overview
CPT 0606U: Osmotic Gradient Ektacytometry for Red Cell Membrane Disorders
CPT code 0606U designates a Proprietary Laboratory Analyses (PLA) test for Osmotic Gradient Ektacytometry, a specialized assay that quantifies red blood cell deformability across osmotic gradients to identify red cell membrane disorders. As a PLA code, 0606U maps to a single proprietary test performed by Cincinnati Children's Clinical Laboratories and RR Mechatronics, making it critical for coverage and billing clarity for rare hematologic evaluations. Nationally, PLA codes like 0606U matter because they pinpoint unique diagnostics with limited providers and distinct clinical value for diagnosing hereditary and acquired membrane defects.
Key payers in the analysis include Aetna, Blue Cross Blue Shield, Cigna, UnitedHealthcare, and Medicare. Readers will learn the clinical context in which the test is used, the expected site of service (clinical and reference laboratories), and which stakeholders commonly manage billing for proprietary lab assays. The publication also provides benchmarks and policy-oriented context relevant to proprietary laboratory codes, including how PLA designation affects coding specificity, payer recognition, and administrative workflows. Where payer-specific coverage or coding guidance is unavailable in the input, the report indicates that the data are not provided. This summary serves clinicians, laboratory administrators, and billing professionals seeking concise guidance about CPT code 0606U and its role in diagnosing red cell membrane disorders.
Billing Code Overview
CPT code 0606U is a Proprietary Laboratory Analyses (PLA) code that applies to a single, specific laboratory test: Osmotic Gradient Ektacytometry performed by Cincinnati Children's Clinical Laboratories and RR Mechatronics. The test quantitatively measures the ability of red blood cells (RBCs) to change shape across varying osmotic conditions using an osmotic gradient ektacytometry method, and results are used to identify red cell membrane disorders.
Service Type: Specialized laboratory diagnostic test (proprietary PLA)
Typical Site of Service: Clinical laboratory / reference laboratory setting, including hospital-based clinical laboratories or specialized outside reference labs that perform the proprietary assay.
Clinical & Coding Specifications
Clinical Context
A 12-year-old child with chronic hemolytic anemia and intermittent jaundice is referred to a hematology clinic for evaluation of suspected hereditary red blood cell membrane disorders after a family history of hereditary spherocytosis. The patient has persistent reticulocytosis, variable splenomegaly on exam, and an abnormal peripheral smear showing spherocytes. The hematologist orders 0606U (Osmotic Gradient Ektacytometry) performed at Cincinnati Children’s Clinical Laboratories using RR Mechatronics equipment to quantify RBC deformability across an osmotic gradient.
Clinical workflow: The clinician documents the indication and relevant history in the chart, obtains informed consent, and orders the test through the electronic health record. A peripheral blood sample is drawn (typically EDTA tube) and sent to the reference lab. The laboratory performs osmotic gradient ektacytometry, producing quantitative curves and indices (e.g., Omin, EImax) that help distinguish hereditary spherocytosis, hereditary elliptocytosis, and other membrane or dehydration-related RBC disorders. Results are transmitted to the ordering provider; the hematologist integrates findings with family history, genetics, and other labs (CBC, reticulocyte count, peripheral smear, hemolysis labs) to confirm diagnosis and guide management such as genetic testing, splenectomy considerations, or supportive care planning.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | When billing separately for the professional interpretation/reporting by a physician if the laboratory bills equipment separately |
TC | Technical component | When billing only for the laboratory technical component (instrumentation, specimen processing) if separate from professional interpretation |
59 | Distinct procedural service | When another independently identifiable service not ordinarily billed with 0606U is performed on the same day and meets documentation criteria |
90 | Reference laboratory | When 0606U is performed by a reference laboratory and the ordering provider bills separately for sample collection |
91 | Repeat clinical diagnostic laboratory test | When the exact same test is repeated on the same day for verification of results |
G0 | Services related to clinical trials | When the test is performed as part of a qualifying clinical trial (applicable for some payors) |
QW | CLIA-waived test (not typical) | Rarely applicable; only if a waived version existed and CLIA rules permit separate billing |
PO | Purchased diagnostic test | When the performing lab purchases the test from another entity and reports accordingly (used in some payor policies) |
52 | Reduced services | When a limited or partial test is performed and documentation supports reduced service (used sparingly) |
22 | Increased procedural services | When work or complexity substantially exceeds typical for 0606U and documentation supports additional payment |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207RH0000X | Pediatric Hematology-Oncology | Common ordering specialty for hereditary RBC membrane disorder evaluation |
207RG0300X | Adult Hematology | Adult hematologists order and interpret specialized RBC testing |
2080P0005X | Clinical Pathology | Pathologists oversee specialized hematology laboratory testing and quality |
208000000X | Clinical Laboratory | Laboratory directors and diagnostics specialists responsible for performing PLA tests |
207L00000X | Pediatric Medicine | Pediatricians may initiate referral and order testing for suspected inherited anemia |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
D58.0 | Hereditary spherocytosis | Primary indication for osmotic gradient ektacytometry to assess RBC membrane deformability and confirm membrane disorder |
D59.0 | Autoimmune hemolytic anemia | Differential diagnosis for hemolysis; ektacytometry can help differentiate immune-mediated versus membrane structural causes |
D58.2 | Hereditary elliptocytosis | Ektacytometry helps characterize elliptocytosis-associated changes in RBC deformability |
D59.9 | Hemolytic anemia, unspecified | When hemolysis is present but etiology is undetermined; 0606U can contribute to diagnostic clarification |
R71.0 | Elevated erythrocyte sedimentation rate (if applicable) | Ancillary inflammatory marker sometimes reported during diagnostic workup of hemolytic processes |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
80053 | Comprehensive metabolic panel | Performed to assess organ function and baseline metabolic status when evaluating hemolytic anemia; ordered alongside diagnostic testing |
85025 | Complete blood count (CBC) with automated differential | Provides RBC indices, hemoglobin, hematocrit, and reticulocyte count essential to initial evaluation before 0606U |
85014 | Reticulocyte count | Evaluates bone marrow response and hemolysis severity; commonly ordered with osmotic gradient testing |
85300 | Prothrombin time | Part of hemolysis and preoperative assessment in patients being considered for splenectomy; sometimes included in the pre-evaluation panel |
88233 | Flow cytometry for red cell antigen(s) or membrane proteins | Used in differential diagnostic workflows (e.g., to assess band 3/ankyrin deficiencies or other membrane protein abnormalities) when available |
81479 | Unlisted molecular pathology procedure | Used for genetic testing (targeted sequencing or panel) for hereditary RBC membrane disorders when a specific CPT for the genetic test is not available |