Summary & Overview
HCPCS G9911: Clinically Node-Negative Invasive Breast Cancer (T1/T2)
HCPCS Level II code G9911 designates clinically node-negative invasive breast cancer limited to T1 or T2 tumor size categories (T1N0M0 or T2N0M0), applicable both before and after neoadjuvant systemic therapy. The code captures a specific clinical staging scenario used in oncology care pathways and treatment planning for early-stage invasive breast cancer. Nationally, precise coding of staging-related conditions influences care coordination, quality measurement, and documentation tied to surgical and systemic therapy decisions.
Key payers addressed in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of the clinical context for G9911, typical sites of service, and which payers commonly engage with this classification in coverage and claims processing. The publication outlines expected benchmarks and reporting purposes for this code, highlights relevant policy considerations that affect billing and care pathways, and situates the code within multidisciplinary oncology workflows. Where input data is incomplete, the report notes missing elements explicitly to guide further data collection. This summary is written for a national audience and focuses on coding implications, documentation needs, and the role of G9911 in staging and treatment sequencing for early invasive breast cancer.
Billing Code Overview
HCPCS Level II code G9911 describes clinically node negative (T1N0M0 or T2N0M0) invasive breast cancer, documented either before or after neoadjuvant systemic therapy. This designation refers to invasive breast tumors that are clinically assessed as having no regional lymph node involvement (N0) at the time of evaluation, limited to tumor sizes consistent with T1 or T2 staging.
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Service type: Diagnostic and staging characterization of invasive breast cancer for clinical classification and treatment planning.
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Typical site of service: Oncology clinic, breast surgery clinic, outpatient hospital or ambulatory surgical center, and multidisciplinary cancer care settings where staging and treatment sequencing decisions are made.
Clinical & Coding Specifications
Clinical Context
A 54-year-old woman presents to a breast surgical oncology clinic after screening mammography and diagnostic ultrasound identified a 2.1 cm irregular mass in the left breast. Core needle biopsy confirms invasive ductal carcinoma. Physical exam and targeted imaging show no palpable axillary lymphadenopathy and imaging suggests no suspicious nodes. Clinical stage is cT2N0M0. The patient elects definitive breast-conserving surgery with sentinel lymph node biopsy. Alternatively, this code also applies to a patient who received neoadjuvant systemic therapy (chemotherapy or endocrine therapy) for a clinically node-negative invasive breast carcinoma (initially T1N0M0 or T2N0M0), and is undergoing surgery after completion of therapy.
Workflow: Preoperative evaluation includes diagnostic imaging, biopsy confirmation, and multidisciplinary review. On the day of surgery the operative team documents clinical node-negative status (cN0) before incision. Pathology and intraoperative sentinel node assessment (if performed) are documented. Postoperative oncologic planning (adjuvant radiation, systemic therapy) follows pathology results.
Coding Specifications
| Modifier | Description | When to Use |
|---|---|---|
22 |