ICD-10 Code C90.1 – Plasma cell leukemia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C90.1 – Plasma cell leukemia
What it is
C90.1 identifies plasma cell leukemia, an aggressive plasma cell malignancy with circulating plasma cells in the blood. Use it when the diagnosis is specifically documented.
Clinical signs
Clinical features vary; refer to documentation. Common findings may include anemia, bone pain, weakness, renal impairment, and evidence of plasma cells in peripheral blood.
When to use this code
Use C90.1 when the provider documents plasma cell leukemia, including primary or secondary disease if that is the stated diagnosis. It also fits cases described as leukemic transformation of plasma cell myeloma when documented as plasma cell leukemia. Check documentation if the record only says multiple myeloma or another plasma cell disorder.
Do not use for
Do not use this code for multiple myeloma without leukemic involvement, solitary plasmacytoma, or other plasma cell dyscrasias. If the diagnosis is unclear, check documentation.
Coding tip
Assign C90.1 only when the record clearly names plasma cell leukemia; otherwise, query for specificity.