What is ICD-10 code D46.0?

D46.0 is the ICD-10-CM diagnosis code for Refractory anemia without ring sideroblasts, so stated. A bone marrow disorder where red blood cells cannot be produced normally, without the presence of ring sideroblasts (abnormal iron-containing cells). It belongs to the ICD-10-CM chapter for neoplasms (c00-d49). D46.0 is a billable code, meaning it can be reported on a claim as a primary or secondary diagnosis when supported by documentation. D46.0 is part of the FY2026 ICD-10-CM code set published by the CMS National Center for Health Statistics and used on Medicare, Medicaid, and commercial claims in the United States.

Yes. D46.0 is a billable ICD-10-CM code that can be reported on professional and institutional claims as a primary or secondary diagnosis when the provider documentation supports the specific condition described. Billable codes in ICD-10-CM are coded to the highest level of specificity available for the documented diagnosis. D46.0 is current for fiscal year 2026 and remains in the active CMS ICD-10-CM code set published by the National Center for Health Statistics.

Which HCC does D46.0 map to under V28?

D46.0 maps to CMS-HCC V28 HCC 19 (Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers). The category numbers, labels, and conditions come from the CMS-HCC V28 model file for payment year 2026.

2026 ICD-10-CM D46.0: Refractory anemia without

D46.0 maps to CMS-HCC V28 19. A source-labeled RAF reference is available. Documentation must support MEAT. MEAT criteria · RAF Calculator · HCC coding software

ICD-10-CM Code View

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Digital ICD-10 code-book layout with official code detail, always-visible risk models, Code Trumping, and Buddy coding guidance.

Code lookupD46.0Effective periodFY2026 Apr Update (Apr 1-Sep 30)

FY 2026 Apr update / Neoplasms (C00-D49) / Neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes (D37-D48)

D46.0

Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidance

Refractory anemia without ring sideroblasts, so stated

A bone marrow disorder where red blood cells cannot be produced normally, without the presence of ring sideroblasts (abnormal iron-containing cells).

Buddy Insight

Refractory anemia without ring sideroblasts is a subtype of myelodysplastic syndrome characterized by ineffective erythropoiesis with dysplastic changes in the bone marrow.

CMS-HCC V28

Mapped

HCC 19

Myelodysplastic Syndromes, Mu...

Code-level coefficient reference

CMS-HCC V24

Historical

Not used for standard CY2026 Medicare Advantage payment. Select a historical period to review V24.

Not used for CY2026 payment

ACA/HHS

Mapped

HCC 067

HHS-HCC 067 adult, RAF varies...

Code-level coefficient reference

ESRD/PACE

Mapped

HCC 46

Severe Hematological Disorders

Code-level coefficient reference

RXHCC

Mapped

HCC 19

Leukemias and Other Hematolog...

Code-level coefficient reference

Code Book Path

Official

D46Myelodysplastic syndromes

D46.0Refractory anemia without ring sideroblasts, so stated

Inclusion Terms

Official

Refractory anemia without sideroblasts, without excess of blasts

Excludes 2

Official

drug-induced aplastic anemia (D61.1)

Related Child Codes

Official

D46.1Refractory anemia with ring sideroblasts

D46.2Refractory anemia with excess of blasts [RAEB]

D46.4Refractory anemia, unspecified

D46.9Myelodysplastic syndrome, unspecified

D46.ARefractory cytopenia with multilineage dysplasia

Includes

Official

ICD-10-CM does not list Includes notes for D46.0 in this effective period.

Excludes 1

Official

ICD-10-CM does not list Excludes 1 notes for D46.0 in this effective period.

Code First

Official

ICD-10-CM does not list Code First sequencing instructions for D46.0 in this effective period.

Use Additional

Official

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

Code Also

Official

ICD-10-CM does not list Code Also instructions for D46.0 in this effective period.

Buddy Documentation Tip

HCC Buddy guidance

Documentation must include bone marrow biopsy results confirming dysplastic changes in the erythroid lineage without ring sideroblasts, blast percentage below 5%, and cytogenetic analysis results.

Peripheral blood counts showing persistent anemia despite adequate nutritional supplementation should be documented.

World Health Organization classification criteria should be referenced.

MEAT Support

HCC Buddy guidance

Documentation must include bone marrow biopsy results confirming dysplastic changes in the erythroid lineage without ring sideroblasts, blast percentage below 5%, and cytogenetic analysis results.

Peripheral blood counts showing persistent anemia despite adequate nutritional supplementation should be documented.

World Health Organization classification criteria should be referenced.

Audit Caution

HCC Buddy guidance

Do not assign this code for nutritional anemias or anemias of chronic disease that respond to treatment.

The term 'refractory' indicates failure to respond to standard anemia therapies, not simply difficult-to-treat anemia.

Ensure bone marrow biopsy confirms the absence of ring sideroblasts before using D46.0 instead of D46.1.

Common Mistakes

HCC Buddy guidance

D46.1 (refractory anemia with ring sideroblasts) requires documentation of ring sideroblasts on bone marrow examination.

D46.9 (myelodysplastic syndrome, unspecified) should not be used when the specific subtype is documented.

D64.9 (anemia, unspecified) is for anemias without myelodysplastic features.

D46.20 (refractory anemia with excess blasts, unspecified) indicates higher blast counts.

Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →

Is D46.0 an HCC code?

Yes. D46.0 (Refractory anemia without ring sideroblasts, so stated) maps to HCC 19, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers under the CMS-HCC V28 risk adjustment model, with a source-labeled community non-dual aged reference coefficient of 1.798. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes. It is billable for payment year 2026.

Coder answer: D46.0 is billable and maps to V28 HCC 19, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.

Code: D46.0
Description: Refractory anemia without ring sideroblasts, so stated
HCC (V28): HCC 19 — Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers
RAF reference coefficient: 1.798
Billable: Yes
Payment year: 2026

HCC Category Mapping

V28HCC 19, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers

1.798

ESRDHCC 46, Severe Hematological Disorders

Not separately weighted

RxHCCHCC 19, Leukemias and Other Hematologic Cancers

Not separately weighted

These are source-labeled model coefficients, not member totals. A category may still be removed by hierarchy or model cleanup rules. Weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. Actual per-patient RAF contribution depends on member context, hierarchy and cleanup rules, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains available for historical review.

Work D46.0 in the Code Book — tabular path, V28 RAF reference, and MEAT checklist →

MEAT Criteria for D46.0

For D46.0 to count as a valid HCC diagnosis in a given encounter, the provider's documentation must show MEAT: Monitor, Evaluate, Assess, or Treat. A diagnosis from a prior year does not carry forward automatically, it has to be re-documented and supported each calendar year.

MMonitor: signs, symptoms, disease progression, or lab trending documented in the note
EEvaluate: test results, medication response, or physical findings reviewed by the provider
AAssess: explicit mention in the assessment or plan with acknowledgment of status
TTreat: medication, referral, procedure, therapy, or counseling tied to the diagnosis

Only one of M/E/A/T is required to support the code, but the documentation must be specific enough to show that the provider actually addressed D46.0 during that encounter, not just copy-forwarded from a problem list.

Coder workflow notes

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What This Code Means

D46.0 is the ICD-10-CM diagnosis code for refractory anemia without ring sideroblasts, so stated. A bone marrow disorder where red blood cells cannot be produced normally, without the presence of ring sideroblasts (abnormal iron-containing cells). D46.0 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering neoplasms of uncertain behavior, polycythemia vera and myelodysplastic syndromes (d37-d48).

Under the CMS-HCC V28 risk adjustment model, D46.0 maps to Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers (HCC 19) with a source-labeled community, non-dual, aged reference coefficient of 1.798. No V24 mapping is shown for D46.0; use the applicable model and payment year when reviewing the V28 mapping. V28 is the CMS-HCC risk adjustment model that reached 100% phase-in for payment year 2026, replacing V24 which was used during the PY2024–PY2025 transition. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Confirm the absence of ring sideroblasts before assigning this code. Because D46.0 maps to an HCC category, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) before the diagnosis is used for risk adjustment. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.

HCC Buddy maintains structured V28 and V24 mapping, source-labeled coefficient references, and MEAT documentation criteria for D46.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

•Confirm the absence of ring sideroblasts before assigning this code
•This is a myelodysplastic syndrome subtype requiring documentation of cytopenia severity

Clinical Significance

Refractory anemia without ring sideroblasts is a subtype of myelodysplastic syndrome characterized by ineffective erythropoiesis with dysplastic changes in the bone marrow. Patients typically present with persistent anemia unresponsive to iron, vitamin B12, or folate supplementation, and require regular monitoring for disease progression to higher-risk myelodysplastic syndrome subtypes or acute myeloid leukemia.

Documentation Requirements

✓Documentation must include bone marrow biopsy results confirming dysplastic changes in the erythroid lineage without ring sideroblasts, blast percentage below 5%, and cytogenetic analysis results.
✓Peripheral blood counts showing persistent anemia despite adequate nutritional supplementation should be documented.
✓World Health Organization classification criteria should be referenced.

Commonly Confused Codes

•D46.1 (refractory anemia with ring sideroblasts) requires documentation of ring sideroblasts on bone marrow examination.
•D46.9 (myelodysplastic syndrome, unspecified) should not be used when the specific subtype is documented.
•D64.9 (anemia, unspecified) is for anemias without myelodysplastic features.
•D46.20 (refractory anemia with excess blasts, unspecified) indicates higher blast counts.