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C93.1 vs D46.Z

C93.1 (Chronic myelomonocytic leukemia) compared with D46.Z (Other myelodysplastic syndromes), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.

Can these codes be reported together?

No — do not report together. D46.Z carries an Excludes1 note covering C93.1: “chronic myelomonocytic leukemia (C93.1-)”

Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).

Side by side

C93.1Chronic myelomonocytic leukemiaD46.ZOther myelodysplastic syndromes
Billing statusNon-billable header

Report instead: C93.10, C93.11, C93.12

Billable
ClassificationC00-D49 — Neoplasms (C00-D49)C00-D49 — Neoplasms (C00-D49)
DefinitionChronic myelomonocytic leukemia is a non-billable ICD-10-CM category code (C93.1).Other myelodysplastic syndromes is a billable ICD-10-CM diagnosis code (D46.Z).
Includes
monocytoid leukemia
Chronic monocytic leukemia
CMML-1
CMML-2
Use additional code
code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources