C94.00
BillableAcute erythroid leukemia, not having achieved remission
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C94.00 an HCC code?
Yes. C94.00 maps to Metastatic Cancer and Acute Leukemia under the CMS-HCC V28 risk adjustment model (and Metastatic Cancer and Acute Leukemia 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 C94.00
For C94.00 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 C94.00 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C94.00 is the ICD-10-CM diagnosis code for acute erythroid leukemia, not having achieved remission. A rare type of blood cancer where cancer cells develop from red blood cell precursors and have not responded to treatment. C94.00 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, C94.00 maps to Metastatic Cancer and Acute Leukemia (HCC 17) with a community, non-dual, aged base RAF weight of 0.368. Under the older V24 model, C94.00 mapped to the same category but with a base RAF weight of 2.484 — V28 recalibrated weights across the entire model. 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.
Acute erythroid leukemia is a rare subtype; ensure pathology confirms this diagnosis before coding. Because C94.00 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 C94.00 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Acute erythroid leukemia is a rare subtype; ensure pathology confirms this diagnosis before coding
- •The fifth character '0' indicates no remission; document treatment response status
Clinical Significance
Acute erythroid leukemia not having achieved remission is an extremely rare subtype of acute myeloid leukemia where the neoplastic cells arise from erythroid (red blood cell) precursors. Under the current WHO classification, pure erythroid leukemia requires at least 80% erythroid precursors in the bone marrow, making precise pathologic diagnosis essential.
Documentation Requirements
- ✓Bone marrow biopsy with morphology and immunophenotyping must confirm erythroid lineage predominance.
- ✓Documentation should include blast percentage, erythroid precursor percentage, treatment history, and current disease status confirming remission has not been achieved.
- ✓Cytogenetic findings should be noted given frequent complex karyotypes.
Commonly Confused Codes
- •D46.20 (refractory anemia with excess of blasts, unspecified) may present with erythroid hyperplasia but is a myelodysplastic syndrome.
- •C92.00 (acute myeloblastic leukemia) is the standard myeloid leukemia without erythroid predominance.
- •C94.01 and C94.02 are the same disease in remission or relapse.