Alphabetic Index FY2027

D46

Myelodysplastic syndromes

FY2027Chapter 2: Neoplasms/D37–D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

D46 is a non-billable ICD-10-CM code category for myelodysplastic syndromes. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are D46.0 Refractory anemia without ring sideroblasts, so stated; D46.1 Refractory anemia with ring sideroblasts; D46.2 Refractory anemia with excess of blasts [RAEB]; D46.A Refractory cytopenia with multilineage dysplasia and 5 more. Its coding notes include a Use additional code instruction, 1 Excludes1 entry and 1 Excludes2 entry.

Use additional code

Add the listed code as a secondary code, if known.

This code
  • code for adverse effect, if applicable, to identify drug (T36-T50 with fifth or sixth character 5)

Excludes1

Not coded here. The listed conditions generally should not be reported together.

Also from chapter/block level (1 note)
Inherited from D37–D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
  • neoplasms of unspecified behavior (D49.-)

Excludes2

Not included here. Both codes may be reported if the patient has both conditions.

This code
  • drug-induced aplastic anemia (D61.1)

Notes

Also from chapter/block level (9 notes)
Inherited from D37–D48 Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
  • Categories D37-D44, and D48 classify by site neoplasms of uncertain behavior, i.e., histologic confirmation whether the neoplasm is malignant or benign cannot be made.
Inherited from Chapter 2 Neoplasms
  • Functional activity
  • All neoplasms are classified in this chapter, whether they are functionally active or not. An additional code from Chapter 4 may be used, to identify functional activity associated with any neoplasm.
  • Morphology [Histology]
  • Chapter 2 classifies neoplasms primarily by site (topography), with broad groupings for behavior, malignant, in situ, benign, etc. The Table of Neoplasms should be used to identify the correct topography code. In a few cases, such as for malignant melanoma and certain neuroendocrine tumors, the morphology (histologic type) is included in the category and codes.
  • Primary malignant neoplasms overlapping site boundaries
  • A primary malignant neoplasm that overlaps two or more contiguous (next to each other) sites should be classified to the subcategory/code .8 ('overlapping lesion'), unless the combination is specifically indexed elsewhere. For multiple neoplasms of the same site that are not contiguous, such as tumors in different quadrants of the same breast, codes for each site should be assigned.
  • Malignant neoplasm of ectopic tissue
  • Malignant neoplasms of ectopic tissue are to be coded to the site mentioned, e.g., ectopic pancreatic malignant neoplasms are coded to pancreas, unspecified (C25.9).

More specific codes under D46 9