C93.31
BillableJuvenile myelomonocytic leukemia, in remission
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is C93.31 an HCC code?
Yes. C93.31 maps to Lung and Other Severe Cancers under the CMS-HCC V28 risk adjustment model (and Lung and Other Severe Cancers 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 C93.31
For C93.31to 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 C93.31 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
C93.31 is the ICD-10-CM diagnosis code for juvenile myelomonocytic leukemia, in remission. A rare type of blood cancer in children called juvenile myelomonocytic leukemia where the cancer has responded to treatment and is no longer detectable. C93.31 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, C93.31 maps to Lung and Other Severe Cancers (HCC 20) with a community, non-dual, aged base RAF weight of 0.000. Under the older V24 model, C93.31 mapped to the same category but with a base RAF weight of 0.973 — 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.
Remission status must be documented in the medical record; confirm the patient has achieved complete or partial remission. Because C93.31 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 C93.31 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Remission status must be documented in the medical record; confirm the patient has achieved complete or partial remission
- •This code indicates a positive treatment response and should be used only when remission is confirmed
Clinical Significance
Juvenile myelomonocytic leukemia in remission typically follows allogeneic stem cell transplantation, which is the primary curative therapy for this rare childhood leukemia. Remission after transplant still requires vigilant monitoring, as relapse rates range from 30-50% even after successful engraftment.
Documentation Requirements
- ✓Documentation should confirm remission status with normalization of blood counts, resolution of monocytosis, absence of clonal markers, and if post-transplant, evidence of donor chimerism.
- ✓The basis for remission determination and ongoing surveillance schedule should be clearly stated.