Summary & Overview
CPT 86300: Quantitative Serum Assay for CA 15-3 and CA 27.29
CPT code 86300 denotes a quantitative serum assay for the breast cancer tumor markers CA 15-3 and CA 27.29. These assays are used primarily to monitor disease burden, treatment response, and potential recurrence in patients with known breast cancer. Nationally, tumor marker testing is an important component of oncology laboratory services and contributes to clinical decision-making in surveillance and management.
Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context for CA 15-3/CA 27.29 testing, typical sites of service where the assay is performed, and the common modifiers associated with laboratory billing. The publication summarizes billing considerations and outlines what to expect from payers regarding coverage patterns and administrative handling of laboratory claims.
This briefing provides practical benchmarks and policy-relevant points for revenue cycle teams and laboratory managers, along with clinical context that explains why the assay is ordered and how it fits into patient monitoring pathways. Data not available in the input that would normally appear in payer-specific coverage policies, associated taxonomies, and ICD-10 mapping is noted as unavailable and omitted from detailed tables.
Billing Code Overview
CPT code 86300 describes a quantitative serum assay for cancer antigen CA 15-3 and CA 27.29, tumor markers used primarily in monitoring breast cancer. The procedure measures antigen concentration in the patient’s serum to assess tumor marker levels and help track disease status over time.
Service type: Laboratory test — quantitative tumor marker assay
Typical site of service: Clinical laboratory or hospital lab (blood draw performed in outpatient clinic, hospital, or ambulatory phlebotomy site)
Clinical & Coding Specifications
Clinical Context
A 54-year-old woman with a history of treated stage II invasive ductal carcinoma of the breast presents for routine oncologic surveillance. She has completed surgery and adjuvant therapy and attends periodic follow-up to monitor for recurrence. Her oncologist orders a serum tumor marker panel including measurement of CA 15-3/CA 27.29 to assess trends over time. A phlebotomy draw is performed in the outpatient laboratory; the specimen is processed by the clinical laboratory scientist who runs a quantitative immunoassay for CA 15-3/CA 27.29. Results are reported to the ordering provider and placed in the electronic medical record; significant rises from prior values prompt clinical correlation and potential imaging or additional testing. Typical site of service is an outpatient hospital laboratory or independent clinical laboratory associated with an oncology clinic.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
26 | Professional component | Use when reporting only the professional interpretation component if applicable (rare for most automated immunoassays). |
TC | Technical component | Use when reporting only the technical component of the laboratory test (laboratory performing assay without professional interpretation). |