Summary & Overview
CPT 0018U: ThyraMIR microRNA Thyroid Cancer Risk Assay
CPT code 0018U identifies ThyraMIR, a Proprietary Laboratory Analyses (PLA) molecular diagnostic that analyzes 10 microRNA sequences from a thyroid fine needle aspirate (FNA) and applies an algorithm using patient data to report a positive or negative result for increased thyroid cancer risk. PLA codes matter nationally because they uniquely identify manufacturer- or laboratory-specific tests, enabling payers and providers to track utilization, coverage, and clinical adoption of proprietary diagnostics.
Key payers included in the national coverage context are Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find an overview of the clinical purpose of the assay, the typical service context, and what to expect in payer coverage discussions. The publication summarizes available benchmarks for utilization and reimbursement where reported, highlights policy and coding considerations relevant to PLA codes, and situates the test within thyroid nodule diagnostic workflows. It also outlines common billing modifiers and administrative items for operational planning.
Data not available in the input for associated taxonomies, specific ICD-10 mappings, related codes, and a detailed payer-by-payer coverage matrix.
Billing Code Overview
CPT code 0018U is a Proprietary Laboratory Analyses (PLA) code that describes ThyraMIR by Interpace Diagnostics. The test performs a gene analysis of 10 microRNA sequences from a thyroid fine needle aspirate (FNA) specimen and combines those laboratory results with patient data through an algorithm to report a positive or negative finding for increased thyroid cancer risk.
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Service type: Molecular diagnostic laboratory test with algorithmic interpretation
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Typical site of service: Clinical laboratory processing FNA specimens; results used in outpatient endocrine, cytology, or pathology settings
Clinical & Coding Specifications
Clinical Context
A typical patient is a 35–70-year-old adult presenting to an endocrinologist or otolaryngologist with a thyroid nodule identified on clinical exam or ultrasound. Ultrasound-guided fine needle aspiration (FNA) is performed and cytology returns an indeterminate result (for example, Bethesda category III: atypia of undetermined significance/follicular lesion of undetermined significance, or Bethesda IV: follicular neoplasm/suspicious for a follicular neoplasm). The treating clinician sends residual FNA material or a dedicated FNA specimen to a reference laboratory for molecular testing using the ThyraMIR assay (0018U).
The laboratory receives the FNA specimen, extracts RNA, measures expression of the panel of 10 microRNA sequences, and combines the molecular results with available clinical data through the proprietary algorithm to generate a report indicating increased or decreased risk of thyroid malignancy. The result is returned to the ordering provider, who integrates it with cytology, ultrasound features, patient risk factors, and patient preferences to inform management (surveillance versus diagnostic/therapeutic surgery). Typical sites of service are outpatient clinics, ambulatory surgery centers for the FNA procedure, and independent or hospital-based clinical reference laboratories for the 0018U assay. Billing is performed by the laboratory using the PLA code 0018U with appropriate specimen source and specimen collection documentation retained in the medical record.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the professional interpretation component if the laboratory or pathologist separately bills interpretation from technical processing. |
TC | Technical component | Use when billing only the technical component (laboratory processing) of the test. |
90 | Reference (outside) laboratory | Use when the service is performed by a laboratory other than the billing entity (report from a reference lab). |
91 | Repeat clinical diagnostic laboratory test (Note: not in provided list) | Data not available in the input. |
52 | Reduced services | Use when the test was partially performed or limited by specimen inadequacy or partial processing. |
53 | Discontinued procedure | Use if specimen collection or specimen processing was aborted and test could not be completed. |
59 | Distinct procedural service (Note: not in provided list) | Data not available in the input. |
76 | Repeat procedure by same physician (Note: not in provided list) | Data not available in the input. |
78 | Return to operating room for a related procedure (applicable if surgical follow-up after result) | Use when a separate surgical procedure is required within the postoperative global period that is directly related. |
80 | Assistant surgeon | Use when an assistant surgeon is documented during the FNA or surgical procedure in the associated workflow. |
62 | Two surgeons | Use when two surgeons work together as primary surgeons for a related operative procedure. |
90 | Reference laboratory | Duplicate entry avoided; handled above. |
11 | Increased procedural services | Use when work is substantially greater than typically required for the FNA or specimen handling. |
22 | Unusual procedural services | Use when the laboratory or clinician documents significantly greater complexity for specimen collection or interpretation. |
52 | Reduced services | Duplicate entry avoided; handled above. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207RH0000X | Otolaryngology (ENT) | Common specialty performing thyroid FNA and coordinating testing. |
207K00000X | Endocrinology | Frequently orders molecular testing for indeterminate thyroid cytology to guide management. |
2080P0800X | Pathology | Pathologists oversee cytology interpretation and coordinate molecular testing workflows. |
261QM0800X | Clinical Laboratory & Laboratory Medicine | Laboratories performing 0018U testing and reporting results. |
207L00000X | General Surgery | Surgeons managing thyroid nodules and using results to decide on operative intervention. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
E04.1 | Nontoxic single thyroid nodule | Common indication for FNA and subsequent molecular testing with 0018U when cytology is indeterminate. |
E04.2 | Nontoxic multinodular goiter | Individual nodules may be sampled and molecular testing used for risk stratification. |
E07.9 | Disorder of thyroid, unspecified | Used when a specific thyroid disorder is not yet defined and FNA/molecular testing is pursued. |
C73 | Malignant neoplasm of thyroid gland | Relevant when suspicion for malignancy exists; 0018U helps estimate malignancy risk in indeterminate cytology. |
R22.1 | Localized swelling, mass and lump, neck | Symptom code tied to detection of thyroid nodules leading to FNA and molecular analysis. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
10021 | Fine needle aspiration without imaging guidance | Performed when FNA is done freehand; specimen source for 0018U. |
10022 | Fine needle aspiration with imaging guidance | Performed when ultrasound guidance is used for FNA that provides the specimen for molecular testing with 0018U. |
88312 | Cytopathology, evaluation of fine needle aspirate, including interpretation and report | Cytology interpretation typically reported alongside molecular testing results; helps determine need for 0018U. |
88342 | Immunohistochemistry or special stains, per specimen | May be performed on FNA material in parallel to molecular studies for diagnostic clarification. |
81599 | Unlisted molecular pathology procedure | Occasionally used historically when a PLA code was not available; 0018U supersedes unlisted coding for this proprietary assay. |