ICD-10 Code D46.9 – Myelodysplastic syndrome, unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code D46.9 – Myelodysplastic syndrome, unspecified
What it is
D46.9 identifies a myelodysplastic syndrome that is documented without a more specific subtype. It is a bone marrow disorder in which blood cell production is abnormal, but the record does not name a particular category.
Clinical signs
Clinical features vary; refer to documentation. Common findings in myelodysplastic syndromes include unexplained cytopenias, anemia-related fatigue, easy bruising, or recurrent infections, but the exact pattern depends on the subtype.
When to use this code
Use D46.9 when the provider documents myelodysplastic syndrome and does not specify the subtype. It is also appropriate when the note states MDS NOS, unspecified MDS, or a similar nonspecific diagnosis. If a more detailed subtype is documented, code that specific option instead.
Do not use for
Do not use D46.9 when the chart identifies a specific myelodysplastic syndrome subtype or another cause of cytopenia. Check documentation if the diagnosis is only suspected, ruled out, or not clearly established.
Coding tip
Code the most specific MDS type documented; use D46.9 only when the record truly lacks subtype detail.