C94.6 ICD-10-CM Code: Myelodysplastic disease, not elsewhere classified
C94.6 maps to CMS-HCC V28 19 (RAF 1.798). Documentation must support MEAT. MEAT criteria · RAF calculator · HCC Buddy coding tools
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FY 2026 Apr update / Neoplasms (C00-D49) / Malignant neoplasms of lymphoid, hematopoietic and related tissue (C81-C96)
C94.6
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceMyelodysplastic disease, not elsewhere classified
A blood disorder characterized by abnormal development of bone marrow cells that doesn't fit into other specific myelodysplastic categories.
Buddy Insight
Myelodysplastic disease, not elsewhere classified, captures myelodysplastic conditions that do not meet criteria for specific myelodysplastic syndrome subtypes or other classified myeloid disorders.
CMS-HCC V28
MappedHCC 19
RAF 1.798
CMS-HCC V24
MappedHCC 48
RAF 0.192
ACA/HHS
MappedHCC 75
Varies by metal level
ESRD/PACE
MappedHCC 48
RAF 0.063
RXHCC
MappedHCC 21
RAF 0.410
Code Book Path
Inclusion Terms
Official- Myelodysplastic/myeloproliferative neoplasm, unclassifiable
- Myeloproliferative disease, not elsewhere classified
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for C94.6 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for C94.6 in this effective period.
Excludes 1
Official- leukemic reticuloendotheliosis (C91.4-)
- myelodysplastic syndromes (D46.-)
- personal history of leukemia (Z85.6)
- plasma cell leukemia (C90.1-)
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for C94.6 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for C94.6 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for C94.6 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
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 C94.6 an HCC code?
Yes. C94.6 (Myelodysplastic disease, not elsewhere classified) maps to Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers under the CMS-HCC V28 risk adjustment model (and Coagulation Defects and Other Specified Hematological Disorders under V24), with a community non-dual aged RAF of 1.798. It is billable for payment year 2026.
Coder answer: C94.6 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
- C94.6
- Description
- Myelodysplastic disease, not elsewhere classified
- HCC (V28)
- HCC 19 — Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers
- RAF
- 1.798
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so 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 segment, interactions, and the model year used by the payer. V28 is the CMS-HCC model phased in over payment years 2024–2026; V24 remains in use during the transition and for historical data.
Work C94.6 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for C94.6
For C94.6 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 C94.6 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
C94.6 is the ICD-10-CM diagnosis code for myelodysplastic disease, not elsewhere classified. A blood disorder characterized by abnormal development of bone marrow cells that doesn't fit into other specific myelodysplastic categories. C94.6 sits in the ICD-10-CM chapter for neoplasms (c00-d49), within the section covering malignant neoplasms of lymphoid, hematopoietic and related tissue (c81-c96).
Under the CMS-HCC V28 risk adjustment model, C94.6 maps to Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers (HCC 19) with a community, non-dual, aged base RAF weight of 1.798. Under the older CMS-HCC V24 model, C94.6 maps to Coagulation Defects and Other Specified Hematological Disorders (HCC 48) with a community, non-dual, aged base RAF weight of 0.192. 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.
Use C94.6 when the provider wording supports myelodysplastic disease, not elsewhere classified. Check the FY2026 tabular notes and the full code path before the final code choice. Because C94.6 maps to a payment HCC, the provider's documentation must satisfy MEAT criteria (Monitor, Evaluate, Assess, or Treat) for the encounter to count toward the patient's Medicare Advantage risk adjustment score. 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, RAF weights, and MEAT documentation criteria for C94.6 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use C94.6 when the provider wording supports myelodysplastic disease, not elsewhere classified. Check the FY2026 tabular notes and the full code path before the final code choice.
- •For this DOS, capture the provider's current assessment and the care action documented for myelodysplastic disease, not elsewhere classified. Keep the checklist tied to the note.
- •Do not swap C94.6 with C94.0. The FY2026 tabular describes C94.0 as acute erythroid leukemia. Follow the documented detail.
- •C94.6 maps to V28 HCC 19, Myelodysplastic Syndromes, Multiple Myeloma, and Other Cancers. The mapping does not replace the documentation review. The code still has to match the note.
- •Ask Buddy to show the official notes for C94.6 or compare its code path with C94.0.
Clinical Significance
Myelodysplastic disease, not elsewhere classified, captures myelodysplastic conditions that do not meet criteria for specific myelodysplastic syndrome subtypes or other classified myeloid disorders. This residual category may include overlap syndromes or atypical presentations requiring specialized hematologic evaluation.
Documentation Requirements
- ✓Documentation should describe the specific myelodysplastic features present, why the condition does not fit into established myelodysplastic syndrome categories (D46.-), and the diagnostic workup performed.
- ✓Bone marrow findings, cytogenetic results, and blast percentages should be recorded.
- ✓Treatment status and disease trajectory should be documented.
Commonly Confused Codes
- •D46.
- •codes (myelodysplastic syndromes) should be used when a specific myelodysplastic syndrome subtype is identified. C92.1
- •(chronic myeloid leukemia) and D47.
- •(other neoplasms of uncertain behavior) may have overlapping features. C94.80 (other specified leukemias) is used when leukemic transformation has occurred.