ICD-10 Code C40.80 – Malignant neoplasm of overlapping sites of bone and articular cartilage of unspecified limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C40.80 – Malignant neoplasm of overlapping sites of bone and articular cartilage of unspecified limb
What it is
This code identifies a malignant tumor arising in bone or articular cartilage at overlapping sites of an unspecified limb. Use it when the record documents the site as overlapping and does not specify left or right limb.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include localized pain, swelling, a mass, or reduced function in the affected limb, but the diagnosis should be supported by imaging, pathology, or specialist assessment.
When to use this code
Use C40.80 when the provider documents a primary malignant neoplasm involving overlapping sites of bone and articular cartilage in an unspecified limb. It is appropriate when laterality is not stated and the chart clearly indicates a malignant bone/cartilage tumor. If the site is described more specifically, code to that documented location instead.
Do not use for
Do not use this code for benign bone lesions, metastatic disease, or tumors of a clearly specified limb when a more precise code is available. Check documentation if the record does not confirm malignancy or overlapping site involvement.
Coding tip
Confirm both the malignant nature and the unspecified limb documentation before assigning C40.80.