ICD-10 Code D09 – Carcinoma in situ of other and unspecified sites (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D09 – Carcinoma in situ of other and unspecified sites
What it is
D09 identifies carcinoma in situ, a noninvasive epithelial cancer confined to the original site. Use it when the record documents a malignant-appearing lesion that has not invaded deeper tissue.
Clinical signs
Clinical features vary; refer to documentation. Diagnosis is usually based on pathology showing carcinoma in situ without stromal, basement membrane, or other tissue invasion.
When to use this code
Use D09 when the provider documents carcinoma in situ at an unspecified or other site not named by a more specific code. It is appropriate when pathology confirms in situ disease and the location is not coded elsewhere. Check documentation if the site is unclear.
Do not use for
Do not use D09 for invasive malignancy, dysplasia, or benign lesions. If the record names a specific anatomic site with its own carcinoma in situ code, report that more specific code instead.
Coding tip
Verify both the pathology wording and the exact site before assigning D09.