ICD-10 Code D05.12 – Intraductal carcinoma in situ of left breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D05.12 – Intraductal carcinoma in situ of left breast
What it is
This code identifies ductal carcinoma in situ confined to the left breast. The abnormal cells are present inside the milk ducts and have not invaded surrounding breast tissue.
Clinical signs
Clinical features vary; refer to documentation. It is often found on breast imaging or biopsy, sometimes after an abnormal mammogram or a palpable breast change.
When to use this code
Use D05.12 when the provider documents intraductal carcinoma in situ, ductal carcinoma in situ, or DCIS specifically in the left breast. Code it from pathology, imaging, or operative documentation that clearly identifies the left side.
If the record only says carcinoma in situ of breast without laterality, check documentation before assigning a more specific code.
Do not use for
Do not use this code for invasive breast cancer or for in situ disease of the right breast or unspecified breast. Check documentation if the site or laterality is unclear.
Coding tip
Always verify laterality in the pathology or provider note before coding, because D05.12 is side-specific.