Summary & Overview
CPT 0559U: MammoCheck BF9 Antigen ELISA for Breast Cancer Monitoring
CPT code 0559U denotes a Proprietary Laboratory Analyses (PLA) test for MammoCheck™, a blood‑based ELISA that measures the BF9 antigen to monitor breast cancer response to therapy or disease progression. As a PLA code, 0559U applies only to the single, manufacturer‑specific test produced by Milagen Inc., and it is used for reporting when that unique assay is performed. Nationally, PLA codes like 0559U are important because they enable distinct billing and tracking for proprietary diagnostics that may have unique clinical roles or coverage considerations.
Key payers discussed include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise synopsis of the clinical purpose of the test and where it is typically performed, plus an overview of payer coverage considerations and coding context. The publication covers benchmarks and payer policy themes relevant to proprietary laboratory assays, summarizes common modifiers reported with this code, and provides clinical context for how BF9 measurements are intended to inform therapeutic monitoring. Data not available in the input will be explicitly noted where applicable.
Billing Code Overview
CPT code 0559U is a Proprietary Laboratory Analyses (PLA) code that is specific to a single commercial test: MammoCheck™ from Milagen Inc. The test is a blood‑based enzyme‑linked immunosorbent assay (ELISA) that measures the BF9 antigen protein level in a patient’s serum. Results are used to assess whether breast cancer is responding to therapy or showing signs of progression or regression.
Service Type: Proprietary laboratory analysis / serum protein assay (ELISA)
Typical Site of Service: Clinical laboratory or outpatient phlebotomy collection site with laboratory processing
Clinical & Coding Specifications
Clinical Context
A typical patient scenario involves a woman with a history of diagnosed breast carcinoma who is undergoing systemic therapy and requires monitoring for treatment response. A medical oncologist orders the proprietary blood-based test MammoCheck™ (0559U) to measure serum levels of the BF9 antigen via ELISA. A phlebotomy draw is performed in an outpatient oncology clinic, hospital outpatient lab, or independent clinical laboratory. The specimen is processed and sent to Milagen Inc. (the performing laboratory/manufacturer) for analysis. Results are returned to the ordering oncologist and used as an adjunctive objective marker to help evaluate tumor response, detect biochemical progression, or support decisions about imaging follow-up or therapy modification. Typical encounters include surveillance visits during chemotherapy, targeted therapy, or endocrine therapy, and during evaluation of suspected progression when imaging findings are equivocal.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
00 | Default, no modifier appended; service without special circumstances | Use when reporting the test under routine circumstances without special reporting needs |
22 |