ICD-10 Code C79.51 – Secondary malignant neoplasm of bone (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C79.51 – Secondary malignant neoplasm of bone
What it is
C79.51 identifies metastatic cancer that has spread to the bone from a primary tumor elsewhere. Use it when the record clearly documents secondary malignant involvement of bone.
Clinical signs
Clinical features vary; refer to documentation. Common findings include bone pain, pathologic fracture, or imaging evidence of metastatic bone lesions.
When to use this code
Use C79.51 when the provider documents secondary malignant neoplasm in bone, including vertebrae, ribs, pelvis, or other skeletal sites. Code it from pathology, imaging, or oncology notes when the metastatic site is specified. You may need additional codes for the primary malignancy.
Do not use for
Do not use this code for primary bone cancer or benign bone lesions. If the chart only says “metastatic cancer” without a confirmed bone site, check documentation.
Coding tip
Always verify the primary cancer site and the exact metastatic bone location before final coding.