C94.6
BillableMyelodysplastic disease, not elsewhere classified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C94.6 an HCC code?
Yes. C94.6 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).
HCC Category Mapping
RAF weights shown are the community, non-dual, aged base weights from the CMS risk adjustment model file. 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.
MEAT Criteria for C94.6
For C94.6to 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.
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 this code only when the myelodysplastic disease cannot be classified into more specific subtypes. 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
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.