Inflammatory Breast Cancer (IBC) Coding Tip

New ICD-10 Codes for Inflammatory Breast Cancer (IBC) – Effective October 1, 2025 

As of October 1, 2025, three new ICD-10 codes are now available for use to improve accuracy in reporting Inflammatory Breast Cancer (IBC). Coders should begin applying these codes to ensure precise documentation and compliance with current coding standards.

• C50.A0 – Malignant inflammatory neoplasm of unspecified breast 
• Used when documentation confirms inflammatory breast cancer (IBC) but does not specify which breast is affected; supports accurate reporting when laterality is not documented.
• C50.A1 – Malignant inflammatory neoplasm of left breast 
• Identifies confirmed inflammatory breast cancer involving the left breast, allowing precise coding that reflects the disease’s location and aids in treatment tracking.
• C50.A2 – Malignant inflammatory neoplasm of right breast 
• Used to report inflammatory breast cancer of the right breast, improving data accuracy for diagnosis, outcomes monitoring, and research purposes.

Clinical Presentation and Challenges in Diagnosing Inflammatory Breast Cancer

IBC is a rare but aggressive form of breast cancer, accounting for approximately 1–5% of cases in the U.S. Unlike typical breast cancers, IBC often presents without a detectable lump. Instead, symptoms include: 

• Skin changes such as redness, swelling, or bruising 
• “Peau d’orange” texture (pitted skin resembling an orange peel) 
• Tenderness or burning sensation 

Due to its atypical presentation, IBC is frequently misdiagnosed as mastitis and often detected at advanced stages (III or IV). It disproportionately affects women under 40, particularly African American and Black women, and is associated with excess body weight. 

Previously, providers had limited options for coding IBC, often defaulting to malignancy by site breast cancer codes without specifying type. These new codes will enhance clinical documentation, support better tracking of disease progression, and improve access to appropriate treatment. 

Thanks to advocacy efforts by the IBC Research Foundation and Susan G. Komen, these updates aim to improve data collection and advance research. 

Melanie Perrault, RHIA, CDIP, CCS 

Senior Consultant, Audit at UASI

Melanie Perrault is a Senior Consultant in Quality at UASI, with extensive expertise in inpatient coding, CDI, and documentation integrity. She brings a strong educator’s mindset to her coding tips, helping coders and CDI teams strengthen clinical clarity, accuracy, and audit-ready compliance. 

Works Cited

Susan G. Komen. (n.d.). IBC Provider Guide.
Available at https://www.komen.org/wp-content/uploads/IBC_Guide_082824.pdf