D46.9 (Myelodysplastic syndrome, unspecified) compared with D72.11 (Hypereosinophilic syndrome [HES]), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Not coded here — these two are mutually exclusive.
“preleukemia (syndrome) (D46.9)”
An Excludes1 note means the two conditions cannot occur together, so the pair should not be reported for the same encounter. The sole exception is when the conditions are documented as unrelated to each other.
Source: CMS ICD-10-CM tabular instructional notes; ICD-10-CM Official Guidelines, Section I.A.12.a
No — do not report together. D72.11 carries an Excludes1 note covering D46.9: “preleukemia (syndrome) (D46.9)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
| D46.9Myelodysplastic syndrome, unspecified | D72.11Hypereosinophilic syndrome [HES] | |
|---|---|---|
| Billing status | Billable | Non-billable header |
| Classification | C00-D49 — Neoplasms (C00-D49) | D50-D89 — Diseases of the Blood and Blood-forming Organs and Certain Disorders Involving the Immune Mechanism (D50-D89) |
| Definition | Myelodysplastic syndrome, unspecified is a billable ICD-10-CM diagnosis code (D46.9). | Hypereosinophilic syndrome [HES] is a non-billable ICD-10-CM category code (D72.11). |
| Includes | Myelodysplasia NOS | — |
| 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