Summary & Overview
CPT 0023U: LeukoStrat CDx FLT3 Mutation Assay
CPT code 0023U designates the LeukoStrat® CDx FLT3 Mutation Assay, a proprietary molecular pathology test that detects mutations in the FLT3 gene to inform treatment planning for patients with acute myelogenous leukemia (AML). As a PLA code, 0023U maps to a single manufacturer's test and is used for reporting the specific diagnostic service performed by Invivoscribe Technologies, Inc. The code matters nationally because FLT3 mutation status is a critical therapeutic and prognostic marker in AML care and influences targeted therapy eligibility and clinical decision-making.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield plans, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for FLT3 testing, the significance of a proprietary PLA code, and what to expect in payer coverage discussions. The publication provides benchmarks and comparative policy highlights, including how PLA coding affects billing specificity, common modifiers used when reporting lab services, and implications for laboratory and oncology service lines.
The report is intended for coding professionals, laboratory directors, oncology clinicians, and policy analysts seeking a national-level summary of the code's purpose, payer landscape, and operational considerations related to the use of a manufacturer-specific molecular diagnostic assay.
Billing Code Overview
CPT code 0023U is a Proprietary Laboratory Analyses (PLA) code that describes the LeukoStrat® CDx FLT3 Mutation Assay by Invivoscribe Technologies, Inc. The test is a molecular pathology assay designed to identify mutations in the FLT3 gene to aid treatment planning for patients with acute myelogenous leukemia (AML).
Service type: Molecular pathology / diagnostic laboratory testing
Typical site of service: Clinical laboratory or outpatient laboratory facility, often ordered by oncology providers and performed by the manufacturer's laboratory or certified diagnostic laboratories.
Clinical & Coding Specifications
Clinical Context
A 62-year-old patient with newly diagnosed acute myelogenous leukemia (AML) undergoes molecular profiling to guide initial therapy selection. The oncology team orders the LeukoStrat® CDx FLT3 Mutation Assay (0023U) on a peripheral blood or bone marrow specimen to detect activating FLT3 internal tandem duplications (ITD) and tyrosine kinase domain (TKD) mutations. The clinical workflow begins with specimen collection by the hematology/oncology clinic or inpatient team, accessioning at the hospital or reference laboratory, and performance of the proprietary PCR-based assay in the performing laboratory. Results are reported to the treating hematologist/oncologist and incorporated into treatment planning, such as selection of FLT3-targeted tyrosine kinase inhibitors, enrollment in targeted therapy clinical trials, or risk stratification for transplant referral. Typical sites of service include hospital outpatient departments, inpatient hospital settings, and independent clinical reference laboratories. Common interacting providers include hematologist/oncologists, pathologists, oncology nurses, and laboratory molecular technologists.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Not a valid modifier for professional billing; placeholder | Data not applicable for separate reporting; not used clinically |
11 | Normal, uncomplicated service | Rarely applied to PLA laboratory codes; not typically used for 0023U
22 | Increased procedural services | Use when laboratory provides substantially increased technical effort beyond standard; approvals vary by payer
26 | Professional component | Use when only the interpretive/professional component of the test is billed separately by a physician or molecular pathologist
52 | Reduced services | Use if the test is partially performed or limited relative to the full procedure
53 | Discontinued procedure | Use if testing was started but discontinued prior to meaningful analysis
62 | Two surgeons/dual attending providers | Not commonly applicable to a lab-based PLA; rarely used
78 | Return to operating/procedure room for a related procedure following initial procedure | Not applicable to this laboratory assay
AD | Advanced Diagnostic Laboratory Test (ADLT) indicator | Use when the test meets ADLT criteria and payer requires this modifier for identification
QK | First available laboratory performance component of a split-service (if applicable) | Use when the performing lab bills only their portion of a split technical service according to payer rules
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207RH0000X | Hematology/Oncology | Ordering and interpreting clinician for AML molecular testing |
2085P0200X | Clinical Pathology | Laboratory medical director or molecular pathologist overseeing testing quality and interpretation
293QQ0400X | Molecular Diagnostics Laboratory | Performing laboratory specialty for proprietary molecular assays
225100000X | Clinical Laboratory | General performing laboratory technicians and managers involved in specimen processing
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
C92.0 | Acute myeloblastic leukemia not having achieved remission | Primary indication for FLT3 mutation testing to guide initial therapy selection and prognostication |
C92.00 | Acute myeloblastic leukemia not having achieved remission, without maturation | Specific AML subtypes where FLT3 status is clinically informative
C92.01 | Acute myeloblastic leukemia not having achieved remission, with maturation | FLT3 mutations influence treatment choices across AML subtypes
C92.02 | Acute myeloblastic leukemia not having achieved remission, with myelodysplasia-related changes | FLT3 testing contributes to risk stratification and therapeutic decisions
D46.9 | Myelodysplastic syndrome, unspecified | In cases of transformation suspicion, FLT3 testing may be used when AML evolution is considered
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
80999 | Unlisted chemistry procedure | Occasionally used when billers need an unlisted chemistry code for ancillary testing not captured by PLA reporting workflows; generally not appropriate when 0023U exists |
88342 | Immunohistochemistry or special staining, per specimen; initial single antibody stain | May be performed on bone marrow biopsy specimens for AML subclassification complementary to molecular testing
81275 | BCR-ABL1 (e13a2 and e14a2) (eg, chronic myelogenous leukemia) | Other hematologic molecular tests commonly ordered alongside comprehensive mutation panels, though not specific to FLT3
0014U | Example PLA code for another proprietary molecular assay | Other PLA codes for hematologic malignancy testing may be ordered in parallel for comprehensive profiling
0001M | Example molecular pathology multianalyte assay code | Multigene panels and companion diagnostics are commonly part of the same diagnostic workflow as 0023U