ICD-10 Code C79.52 – Secondary malignant neoplasm of bone marrow (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C79.52 – Secondary malignant neoplasm of bone marrow
What it is
C79.52 identifies metastatic cancer that has spread to the bone marrow. Use it when the malignancy is secondary, not a primary bone marrow cancer.
Clinical signs
Clinical features vary; refer to documentation. Commonly, records may note marrow involvement confirmed by imaging, biopsy, or pathology, with findings attributable to metastatic disease.
When to use this code
Use C79.52 when the provider documents secondary malignant involvement of the bone marrow. It is appropriate for metastatic disease to marrow from another primary site, including cases confirmed on biopsy or clearly stated in the assessment.
Code the primary malignancy separately, when known, and follow sequencing rules for the encounter. If the record only says “metastatic cancer” without a site, check documentation before assigning this code.
Do not use for
Do not use C79.52 for primary bone marrow neoplasms, leukemia, or nonspecific bone metastasis without marrow involvement. Check documentation if the site of spread is unclear.
Coding tip
Verify that the provider documents bone marrow as the metastatic site, not just bone or skeletal metastasis.