ICD-10 Code C93.1 – Chronic myelomonocytic leukemia (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C93.1 – Chronic myelomonocytic leukemia
What it is
C93.1 identifies chronic myelomonocytic leukemia, a clonal blood cancer with features of both myelodysplastic and myeloproliferative disorders. It involves persistent monocytosis and abnormal marrow production.
Clinical signs
Common findings include sustained monocytosis, anemia, thrombocytopenia, or leukocytosis. Clinical features vary; refer to documentation for marrow findings, splenomegaly, or other supporting evidence.
When to use this code
Use C93.1 when the provider documents chronic myelomonocytic leukemia or CMML. Apply it for confirmed diagnoses in outpatient, inpatient, or problem-list documentation.
Do not use it for unspecified monocytosis, other myelodysplastic syndromes, or acute leukemia unless CMML is specifically documented. Check documentation when the record is unclear.
Do not use for
Do not assign this code for reactive or transient monocytosis, or for leukemia types other than CMML. If the diagnosis is not confirmed, check documentation.
Coding tip
Look for the exact term “chronic myelomonocytic leukemia” or “CMML” in the provider record before coding C93.1.