Total immaturity of WBCs is of clinical importance to identify the morphologies and classify infections, inflammations, or hematology malignancies. HORIBA’s HELO 2.0 and Yumizen H2500 hematology analyzer not only identify the total immaturity of WBCs by the flag but also provide the total immaturity count as LIC parameter, along with its sub-lineage counts as IMG, IMM, and IML. Here, we present a case of Chronic Myelomonocytic Leukemia, presenting the utility of the WBC Total Immaturity parameters that support the diagnostic approach for further confirmations and clinical management, improving laboratory efficiency.