2026 ICD-10-CM Diagnosis Code D46.ZOther myelodysplastic syndromes
ICD-10-CM Codes›C00–D49›D37-D48›D46
- Billable — Valid for Submission
- Risk Adjusts — HCC 19
- Not Chronic
D46.Z is a billable ICD-10-CM diagnosis code for other myelodysplastic syndromes. 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 autosomal dominant aplasia and myelodysplasia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Myelodysplastic syndrome (MDS).
For Medicare Advantage risk adjustment, D46.Z maps to CMS-HCC Category 19 (Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers) under the V28 model, adding a risk factor of about 1.798 for a community, non-dual, aged beneficiary in payment year 2026.
Code Identity
Code Classification
Medicare Risk Adjustment (HCC)Billing
D46.Z maps to a payment category in the CMS-HCC model used to risk-adjust Medicare Advantage payments. Weights are the published community factors for payment year 2026.
Source: CMS Payment Year 2026 risk adjustment mappings and model software. Weights are relative factors, not dollar amounts; a beneficiary's total RAF also includes demographics and interactions. Browse all CMS-HCC categories.
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Autosomal dominant aplasia and myelodysplasia
- Complete deafness
- Congenital deafness
- Hypoplastic myelodysplastic syndrome
- Monosomy 7 syndrome
- Myelodysplastic neoplasm with biallelic TP53 inactivation
- Myelodysplastic neoplasm with low blasts and SF3B1 mutation
- Myelodysplastic syndrome with low blasts
- Unclassifiable myelodysplastic syndrome
Tabular List NotesGuidance
Coding notes and annotation back-references applicable to this code.
Type 1 Excludes
- chronic myelomonocytic leukemia C93.1
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
Index to Diseases and InjuriesGuidance
Alphabetical index entries that point to this code.
specified NEC D46.Z
Myelodysplastic syndrome See Also: Syndrome, myelodysplastic; D46.9
specified NEC D46.Z
Syndrome See Also: Disease;
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
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.Z to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About D46.ZOverview
What is the ICD-10 code for other myelodysplastic syndromes?
The ICD-10-CM code for other myelodysplastic syndromes is D46.Z (sometimes written as D46Z). It is billable on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
Is D46.Z (Myelodysplastic syndromes) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report other myelodysplastic syndromes on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What MS-DRG does D46.Z group to?
When other myelodysplastic syndromes 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.Z?
Under the General Equivalence Mappings, other myelodysplastic syndromes converts to ICD-9-CM 238.75 (myelodysplastic synd NOS). The mapping is approximate, so confirm the match fits the documentation.
What HCC is D46.Z?
D46.Z (other myelodysplastic syndromes) maps to CMS-HCC Category 19 (Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers), commonly written as HCC 19, in the CMS-HCC V28 model used for Medicare Advantage risk adjustment in payment year 2026. It mapped to HCC 46 under the retired V24 model. It also maps in the PACE (CMS-HCC V22), ESRD (V21), and ESRD (V24) models. In the Part D prescription drug model it maps to RxHCC 19.
Does D46.Z risk-adjust for Medicare Advantage payment?
Yes. When documented and reported on a Medicare Advantage encounter, D46.Z adds a risk adjustment factor of about 1.798 to the beneficiary's RAF score for a community, non-dual, aged enrollee (published V28 weights range from 0.957 to 1.989 depending on the payment segment). A more severe related category (HCC 17 and HCC 18) supersedes it when both are reported. See the full factor table on the HCC 19 category page.
