2026 ICD-10-CM Diagnosis Code D46.CMyelodysplastic syndrome with isolated del(5q) chromosomal abnormality

ICD-10-CM Codes›C00–D49›D37-D48›D46

ICD-10-CM D46.C
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

D46.C is a billable ICD-10-CM diagnosis code for myelodysplastic syndrome with isolated del(5q) chromosomal abnormality. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 811 through 812. Coders also document this condition as myelodysplastic syndrome with isolated del. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Myelodysplastic syndrome (MDS).

Code Identity

ICD-10-CM Code
D46.C
Billable Status
Yes — Valid for Submission
Code Describes
Myelodysplastic syndrome with isolated del(5q) chromosomal abnormality
Short Description
Myelodysplastic syndrome w isolated del(5q) chromsoml abnlt
Parent Code
D46
Myelodysplastic syndromes

Code Classification

ChapterC00–D49Neoplasms
SectionD37-D48Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes
CategoryD46Myelodysplastic syndromes
This CodeD46.CMyelodysplastic syndrome with isolated del(5q) chromosomal abnormality

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Myelodysplastic syndrome with isolated del

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Myelodysplastic syndrome with 5q deletion
  • 5q minus syndrome NOS

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Myelodysplastic syndrome
      • with
        • 5q deletion
    • Myelodysplastic syndrome
      • with
        • isolated del (5q) chromosomal abnormality
    • Syndrome
      • 5q minus NOS
    • Syndrome
      • myelodysplastic
        • with
          • 5q deletion
    • Syndrome
      • myelodysplastic
        • with
          • isolated del (5q) chromosomal abnormality

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR NEO068
Myelodysplastic syndrome (MDS)
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Myelodysplastic Syndromes

    clonal hematopoietic stem cell disorders characterized by dysplasia in one or more hematopoietic cell lineages. they predominantly affect patients over 60, are considered preleukemic conditions, and have high probability of transformation into acute myeloid leukemia.

Patient EducationClinical

Myelodysplastic Syndromes

Your bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains immature cells, called stem cells. The stem cells can develop into the red blood cells that carry oxygen through your body, the white blood cells that fight infections, and the platelets that help with blood clotting.

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert D46.C to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
238.74 Myelodyspls syn w 5q del
Exact Match The mapping is direct, with no qualifiers.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About D46.COverview

Is D46.C (Myelodysplastic syndromes) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report myelodysplastic syndrome with isolated del(5q) chromosomal abnormality on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does D46.C group to?

When myelodysplastic syndrome with isolated del(5q) chromosomal abnormality is the principal diagnosis on an inpatient stay, it groups to MS-DRG 811, 812, with relative weights from 0.9182 to 1.4043 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of D46.C?

Under the General Equivalence Mappings, myelodysplastic syndrome with isolated del(5q) chromosomal abnormality converts to ICD-9-CM 238.74 (myelodyspls syn w 5q del). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.