Summary & Overview
CPT 0359U: IsoPSA Prostate PSA Isoform Risk Score
CPT code 0359U designates IsoPSA®, a Proprietary Laboratory Analyses (PLA) assay from Cleveland Diagnostics Inc. that measures structural isoforms of prostate-specific antigen (PSA) in plasma and produces an algorithmic risk score for high-grade prostate cancer. The code is clinically significant because it targets PSA variants that improve specificity for clinically important prostate cancer compared with total PSA alone, affecting diagnostic pathways and downstream use of imaging and biopsy nationally.
Key payers featured include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare and Medicare. Readers will find a concise national overview of coverage patterns and benchmarks, clinical context about the assay’s role in prostate cancer risk stratification, and a summary of coding and billing considerations tied to PLA-designated tests. The publication highlights where 0359U fits in lab-based prostate cancer assessment algorithms, typical sites of service, and practical implications for laboratory and payer workflows.
This analysis is aimed at clinicians, laboratory directors, and payer policy teams seeking a clear, neutral briefing on the code’s clinical purpose, expected use cases, and the types of policy and reimbursement topics that commonly arise with PLA molecular diagnostics.
Billing Code Overview
CPT code 0359U is a Proprietary Laboratory Analyses (PLA) code that applies only to IsoPSA® from Cleveland Diagnostics Inc. The test measures cancer-related structural isoforms (variants) of prostate specific antigen (PSA) in a plasma specimen and uses an algorithmic analysis to report a risk score for high-grade prostate cancer. This assay provides a more specific marker for high-grade prostate cancer than a total PSA test.
Service type: Laboratory — Proprietary molecular diagnostic assay
Typical site of service: Clinical laboratory or reference laboratory using plasma specimens
Clinical & Coding Specifications
Clinical Context
A typical patient is a male aged 50–75 with an elevated or rising prostate specific antigen (PSA) level, prior negative or indeterminate prostate imaging, or a clinically concerning digital rectal exam. The clinician orders 0359U (IsoPSA®) when there is diagnostic uncertainty about the presence of clinically significant (high‑grade) prostate cancer and a more specific biomarker is desired to refine risk of aggressive disease.
Workflow: The patient presents to a urology clinic or primary care office with an abnormal screening PSA or symptoms suggestive of prostate pathology. A venous blood sample (plasma) is collected during the visit and sent to Cleveland Diagnostics Inc. using the manufacturer’s specimen handling instructions. The laboratory performs isoform separation and algorithmic analysis to generate a risk score for high‑grade prostate cancer. Results are returned to the ordering provider and integrated into the chart; the score is used alongside clinical data, imaging (such as multiparametric MRI), and biopsy considerations to inform shared decision‑making about surveillance, further imaging, or prostate biopsy. Typical sites of service include outpatient clinics, hospital outpatient labs, and reference laboratory facilities.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when billing only the physician interpretation component if applicable and the lab separates technical and professional components. |
TC | Technical component | Use when billing only the laboratory/technical component of the test. |
90 | Reference (outside) laboratory | Use when the performing laboratory is an outside/reference lab contracted by the ordering facility. |
91 | Repeat clinical diagnostic lab test (not in provided list) | Data not available in the input. |
QK | CLIA waived test performed in a non‑waived setting (specific QC modifier) | Use when applicable per manufacturer and payer guidance for unique lab testing arrangements (rarely used for PLA). |
QX | CLIA waived test performed by a non‑waived lab personnel (specific QC modifier) | Use per payer/CLIA rules when required for personnel distinction. |
QY | CLIA waived test performed by an appropriately certified provider | Use per payer/CLIA rules when required for personnel distinction. |
90 | Reference (outside) laboratory | Use when the test is performed by an external reference lab (listed to indicate common use). |
AS | Physician assistant, nurse practitioner, or clinical nurse specialist services under supervision of a physician | Use when a PA/NP orders or supervises testing as applicable. |
52 | Reduced services | Use when the test is performed but only a partial panel or limited analysis is completed compared with the full IsoPSA® algorithm. |
53 | Discontinued procedure | Use if specimen collection or testing was started but discontinued for documented clinical reasons. |
59 | Distinct procedural service (not in provided list) | Data not available in the input. |
| Taxonomy Code | Specialty | Notes |
|---|---|---|
| 2084P0800X | Urology | Urologists commonly order IsoPSA® for prostate cancer risk stratification. |
| 207Q00000X | Family Medicine | Primary care physicians order prostate cancer screening tests and may order reflex biomarker testing. |
| 208000000X | Internal Medicine | Internists involved in longitudinal care and cancer screening decisions. |
| 2080P0208X | Hematology/Oncology | Medical oncologists may use results in staging and management planning for suspected high‑grade disease. |
Related Diagnoses
| ICD-10 Code | Description | Clinical Relevance |
|---|---|---|
R97.2 | Elevated prostate specific antigen (PSA) | Primary indication for ordering IsoPSA® to better assess risk of clinically significant prostate cancer. |
N40.0 | Benign prostatic hyperplasia with lower urinary tract symptoms | Common cause of PSA elevation; IsoPSA® helps distinguish benign causes from high‑grade malignancy. |
N45.1 | Chronic prostatitis | Inflammatory conditions can raise PSA; biomarker testing helps contextualize PSA rises. |
C61 | Malignant neoplasm of prostate | Used when cancer is suspected or confirmed; IsoPSA® informs risk stratification for high‑grade disease. |
R10.9 | Abdominal pain, unspecified | Presenting symptom that may prompt prostate evaluation in some clinical scenarios. |
Related CPT Codes
| CPT Code | Description | Relationship to This Procedure |
|---|---|---|
80053 | Comprehensive metabolic panel | Commonly ordered with plasma testing to assess baseline metabolic status prior to procedures or systemic therapy. |
84153 | Prostate specific antigen (PSA); total | Often performed before or alongside 0359U to provide total PSA context for isoform‑based risk calculation. |
84154 | PSA, free | May be ordered with total PSA and IsoPSA® to further refine prostate cancer risk assessment. |
88305 | Level IV surgical pathology, gross and microscopic exam | Performed if prostate biopsy follows risk stratification and tissue is submitted for histopathology. |
72197 | MRI prostate, with or without contrast and with spectroscopy (if applicable) | Multiparametric prostate MRI is often used before biopsy and may be ordered based on an elevated IsoPSA® risk score. |