ICD-10 Code C90.0 – Multiple myeloma (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C90.0 – Multiple myeloma
What it is
C90.0 identifies multiple myeloma, a malignant plasma cell disorder involving the bone marrow. Use it when the record documents this specific diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Commonly documented findings include bone pain, anemia, renal impairment, hypercalcemia, or recurrent infections.
When to use this code
Use C90.0 when the clinician states multiple myeloma, plasma cell myeloma, or myelomatosis. It is appropriate for confirmed active disease and for encounters focused on evaluation, monitoring, or management of the condition. Check documentation if the note only mentions monoclonal gammopathy or another plasma cell disorder.
Do not use for
Do not use C90.0 for MGUS, smoldering myeloma, or solitary plasmacytoma unless the record specifically supports multiple myeloma. If the diagnosis is unclear, check documentation.
Coding tip
Verify the exact plasma cell diagnosis in the assessment, not just abnormal labs or suspected malignancy.