ICD-10 Code D15.0 – Benign neoplasm of thymus (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D15.0 – Benign neoplasm of thymus
What it is
D15.0 identifies a noncancerous tumor arising in the thymus gland, located in the anterior mediastinum. Use it when documentation states a benign thymic neoplasm or thymoma that is not described as malignant.
Clinical signs
Clinical features vary; refer to documentation. Patients may be asymptomatic or have mediastinal mass findings on imaging, and pathology may confirm a benign thymic lesion.
When to use this code
Use D15.0 when the provider documents a benign thymus tumor, benign thymoma, or similar nonmalignant thymic mass. It also fits confirmed benign pathology after biopsy or resection. If the record only says “thymic mass” or is unclear, check documentation before coding.
Do not use for
Do not use this code for malignant thymic tumors, thymic carcinoma, or metastatic disease involving the thymus. Do not assign it for nonspecific chest masses without documentation of thymic origin.
Coding tip
Code the documented pathology exactly; if benign behavior is not stated, verify the final diagnosis before assigning D15.0.