Summary & Overview
CPT 0285U: RadTox™ cfDNA Plasma Test for Oncology Monitoring
CPT code 0285U designates the RadTox™ cfDNA proprietary laboratory assay from DiaCarta Inc., a plasma-based cell-free DNA test that reports quantitative results in ng/mL to aid monitoring of cancer progression and response to therapy. As a PLA code, 0285U is unique to a single manufacturer's test, which matters for coverage, coding clarity, and laboratory billing nationally because payers and providers must identify the exact proprietary assay when submitting claims.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. The publication summarizes payer handling and benchmarks where available, highlights how PLA designation affects coding and documentation, and outlines the clinical context for using a cfDNA plasma assay in oncology monitoring.
Readers will learn the clinical purpose of the test, the service setting and specimen type, typical billing considerations tied to PLA codes, and where to find relevant policy and coverage determinations for major national payers. Data not available in the input will be flagged as such rather than inferred. The focus is national policy and billing practice implications for laboratories, oncology providers, and revenue cycle teams working with proprietary molecular diagnostics.
Billing Code Overview
CPT code 0285U is a Proprietary Laboratory Analyses (PLA) code that applies exclusively to the RadTox™ cfDNA test from DiaCarta Inc. The test analyzes a plasma specimen for specific cell-free DNA sequences and reports results in ng/mL to support monitoring of disease progression and treatment response in patients undergoing cancer therapy.
Service type: Proprietary laboratory molecular diagnostic test (cfDNA analysis)
Typical site of service: Clinical laboratory or off-site reference lab processing using a blood-derived plasma specimen
Data not available in the input.
Clinical & Coding Specifications
Clinical Context
A 62-year-old patient with metastatic non-small cell lung cancer (NSCLC) is undergoing systemic therapy. The oncology team orders the RadTox™ cfDNA test (0285U) to quantify tumor-derived cell-free DNA in plasma, reported in ng/mL, to monitor treatment response and detect molecular progression. A peripheral blood draw is obtained in the outpatient oncology infusion center or clinic; the specimen is sent to DiaCarta Inc. for proprietary laboratory analysis. Results are reviewed by the treating oncologist during follow-up to inform discussions about imaging intervals, potential therapy change, or enrollment in clinical trials. Typical workflow elements include informed consent for blood-based molecular monitoring, phlebotomy by trained staff, specimen handling and shipment per lab instructions, electronic receipt of results in the medical record, and documentation of interpretation and clinical plan by the ordering provider.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | No modifier | Use when no specific modifier applies to the claim for this laboratory test. |
26 | Professional component | Used if billing separates the professional interpretation component from the technical laboratory processing (rare for PLAs but applicable if interpretation is billed separately). |
TC | Technical component | Use when billing only the technical processing of the test (laboratory component) without a professional interpretation fee. |
QK | CLIA waived test performed by a laboratory assistant | Use if applicable personnel qualifications align with payer requirements for a waived test setting (unlikely for a PLA but included for completeness). |
QX | CLIA waived test performed by a non-certified person | Use only per payer rules when non-certified personnel perform portions of testing in waived settings. |
QY | Laboratory test performed in a physician office under CLIA Certificate of Waiver | Use if the lab test meets payer criteria and is legitimately performed in-office under appropriate CLIA status (rare for cfDNA PLAs). |
52 | Reduced services | Use when the test was partially performed or truncated, resulting in reduced service relative to full test. |
53 | Discontinued procedure | Use when collection or testing was initiated but stopped for patient-related reasons prior to completion. |
78 | Unplanned return to the operating/procedure room by same physician following initial procedure | Generally not applicable to this lab test; included for payer reporting when related procedures trigger the modifier. |
80 | Assistant surgeon | Not typically applicable to laboratory billing; use when a documented assistant surgeon participated in a related invasive procedure. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
207RC0000X | Medical Oncology | Oncologists commonly order and interpret cfDNA monitoring tests for cancer management. |
207RH0000X | Hematology/Oncology | Specialists managing solid-tumor or hematologic malignancies who use molecular monitoring. |
363L00000X | Clinical Laboratory Director | Laboratory physicians or directors responsible for oversight of specialized molecular assays. |
208000000X | Internal Medicine | Hospitalists or general internists managing cancer care in some settings and ordering monitoring tests. |
207VP0002X | Oncology Nursing | Advanced practice providers in oncology who frequently order and coordinate testing workflows. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
C34.90 | Malignant neoplasm of unspecified part of bronchus or lung, unspecified | Common indication for plasma cfDNA monitoring in patients with advanced lung cancer receiving systemic therapy. |
C78.7 | Secondary malignant neoplasm of liver and intrahepatic bile duct | Represents metastatic disease sites where cfDNA monitoring may help detect progression. |
C79.9 | Secondary malignant neoplasm of unspecified site | Used when metastasis location is unspecified; cfDNA monitoring aids in systemic disease assessment. |
C80.1 | Malignant (primary) neoplasm, unspecified | Applied when primary site is not confirmed; cfDNA can provide molecular information to guide management. |
Z85.118 | Personal history of other malignant neoplasm of bronchus and lung | Used in surveillance contexts where cfDNA monitoring assesses for recurrence or minimal residual disease. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
36415 | Collection of venous blood by venipuncture | Performed immediately prior to 0285U to obtain the plasma specimen for cfDNA analysis. |
G0477 | Specimen handling for transferred clinical laboratory pathology, per calendar month, technical only | May be used by reference labs or facilities for specimen handling and transfer services associated with specialized testing. |
81025 | Urinalysis; non-automated, without microscopy | Ancillary lab test sometimes ordered concurrently for baseline monitoring; not directly related to cfDNA but common in oncology panels. |
88342 | Immunohistochemistry or special stains; interpretation and report | Performed on tissue specimens when correlated molecular tissue testing complements plasma cfDNA results. |
0001U | Molecular pathology (example PLA) | Other Proprietary Laboratory Analyses codes may be performed alongside or as alternative molecular tests depending on clinical question; these represent similar PLA workflows and billing considerations. |