ICD-10 Code C93.12 – Chronic myelomonocytic leukemia, in relapse (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code C93.12 – Chronic myelomonocytic leukemia, in relapse
What it is
C93.12 identifies chronic myelomonocytic leukemia that has returned after a period of remission. Use it for a recurrent myeloid neoplasm involving both monocytic and granulocytic cell lines.
Clinical signs
Clinical features vary; refer to documentation. Common findings in chronic myelomonocytic leukemia may include persistent monocytosis, cytopenias, splenomegaly, fatigue, or recurrent infections.
When to use this code
Use C93.12 when the provider documents chronic myelomonocytic leukemia as “in relapse,” “recurrent,” or similar language. The relapse status must be clearly stated in the record. If the note only says active disease without relapse, check documentation.
Do not use for
Do not use this code for newly diagnosed chronic myelomonocytic leukemia, remission, or unspecified disease status. Do not assign it when relapse is not documented; check documentation.
Coding tip
Confirm that the record explicitly links the leukemia to relapse before assigning C93.12.