ICD-10 Code D05.1 – Intraductal Carcinoma In Situ of Breast (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D05.1 – Intraductal carcinoma in situ of breast
What it is
This code identifies ductal carcinoma in situ of the breast, a noninvasive breast cancer confined to the milk ducts. You use it when the record shows malignant cells without invasion beyond the duct wall.
Clinical signs
Clinical features vary; refer to documentation. It is often found on mammography as calcifications or an abnormal breast finding, with pathology confirming carcinoma in situ and no evidence of invasive spread.
When to use this code
Use D05.1 when the provider documents intraductal carcinoma in situ, ductal carcinoma in situ, or DCIS of the breast. Code it from pathology or a clearly stated diagnosis, even if the lesion was discovered during screening or workup.
Choose this code only when the record supports a noninvasive breast malignancy. If the note later specifies invasive breast cancer, code the invasive diagnosis instead.
Do not use for
Do not use for lobular carcinoma in situ, benign breast disease, or unspecified breast masses. Check documentation if the pathology report does not clearly state intraductal carcinoma in situ.
Coding tip
Confirm the pathology wording and laterality details in the chart, but code D05.1 only for the in situ diagnosis itself.