ICD-10 Code C40.8 – Malignant neoplasm of overlapping sites of bone and articular cartilage of limb (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C40.8 – Malignant neoplasm of overlapping sites of bone and articular cartilage of limb
What it is
This code identifies a malignant bone or cartilage tumor in a limb when the lesion overlaps adjacent sites and cannot be assigned to one specific bone or joint area.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include localized pain, swelling, or a palpable mass, with imaging or pathology showing a malignant tumor involving overlapping limb sites.
When to use this code
Use C40.8 when the provider documents a malignant neoplasm of bone or articular cartilage in an upper or lower limb and specifies overlapping sites rather than a single anatomic location. Apply it when the record supports a primary malignant tumor, not a benign lesion or metastatic disease. If site details are unclear, check documentation.
Do not use for
Do not use this code for malignant tumors of a single, clearly identified bone site, or for metastatic bone disease. Check documentation if the lesion is described as secondary, unspecified, or outside the limb.
Coding tip
Confirm that the documentation explicitly states “overlapping sites” before assigning C40.8; otherwise, code the most specific documented bone or cartilage site.