ICD-10 Code C41.9 – Malignant neoplasm of bone and articular cartilage, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C41.9 – Malignant neoplasm of bone and articular cartilage, unspecified
What it is
C41.9 identifies a malignant tumor arising in bone or articular cartilage when the exact site is not documented. Use it when the record confirms a primary bone malignancy but does not specify a more precise location.
Clinical signs
Clinical features vary; refer to documentation. Commonly noted findings include persistent bone pain, swelling, or a mass, with imaging or biopsy supporting a malignant bone or cartilage tumor.
When to use this code
Use C41.9 when the provider documents a primary malignant neoplasm of bone or articular cartilage and the site is unspecified. It also fits when the pathology or imaging report confirms malignancy, but the anatomic location is not stated in the chart. If a more specific bone site is documented, code that site instead.
Do not use for
Do not use this code for benign bone lesions, metastatic disease to bone, or cancers of soft tissue. Check documentation if the lesion is in a specific bone, because a more exact code may apply.
Coding tip
Query for the exact bone or cartilage site before assigning C41.9, since unspecified coding should be a last resort.