ICD-10 Code D39.0 – Neoplasm of uncertain behavior of uterus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D39.0 – Neoplasm of uncertain behavior of uterus
What it is
D39.0 identifies a uterine neoplasm whose behavior is uncertain, meaning the pathology cannot clearly be classified as benign or malignant. Use it when the record states uncertain behavior of the uterus or a uterine mass with indeterminate biologic potential.
Clinical signs
Clinical features vary; refer to documentation. Patients may have abnormal uterine bleeding, pelvic pain, or an incidental imaging or pathology finding, but the diagnosis depends on the provider’s classification, not symptoms alone.
When to use this code
Use D39.0 when the provider documents a uterine tumor, neoplasm, or mass as having uncertain behavior, borderline behavior, or indeterminate malignant potential. It may also apply after pathology review when the final impression remains uncertain. If the site is not uterus or the behavior is clearly benign or malignant, choose a different code.
Do not use for
Do not use D39.0 for confirmed malignant uterine neoplasms, benign uterine tumors, or nonspecific uterine symptoms without a documented neoplasm. Check documentation when the pathology or anatomic site is unclear.
Coding tip
Confirm both the uterine site and the “uncertain behavior” wording in the record before assigning D39.0.