ICD-10 Code C56 – Malignant neoplasm of ovary (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C56 – Malignant neoplasm of ovary
What it is
C56 identifies a malignant tumor arising in the ovary. Use it when the record documents primary ovarian cancer, without specifying a more exact site or histologic type.
Clinical signs
Clinical features vary; refer to documentation. Commonly noted findings include pelvic or abdominal mass, bloating, pain, or unexplained abdominal distention, but diagnosis depends on confirmed malignant ovarian disease.
When to use this code
Use C56 when the provider documents malignant neoplasm of the ovary, ovarian cancer, or primary ovarian malignancy. It is appropriate when the chart does not specify laterality or a more detailed subsite. Check documentation if the note describes metastatic disease instead of a primary ovarian tumor.
Do not use for
Do not use this code for benign ovarian cysts, borderline tumors, or cancers that started elsewhere and spread to the ovary. If the origin is unclear, check documentation before assigning C56.
Coding tip
Assign C56 only after confirming the ovary is the primary site and the diagnosis is explicitly malignant.