Z94.84
BillableStem cells transplant status
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Z94.84 an HCC code?
Yes. Z94.84 maps to Graft-Versus-Host Disease and Stem Cell Transplant Complications under the CMS-HCC V28 risk adjustment model (and Major Organ Transplant or Replacement Status 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 Z94.84
For Z94.84 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 Z94.84 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
Z94.84 is the ICD-10-CM diagnosis code for stem cells transplant status. A person who has received a stem cell transplant, which may be used to treat various blood disorders, cancers, or immune conditions. Z94.84 sits in the ICD-10-CM chapter for factors influencing health status and contact with health services (z00-z99), within the section covering persons with potential health hazards related to family and personal history and certain conditions influencing health status (z77-z99).
Under the CMS-HCC V28 risk adjustment model, Z94.84 maps to Graft-Versus-Host Disease and Stem Cell Transplant Complications (HCC 454) with a community, non-dual, aged base RAF weight of 0.000. Under the older CMS-HCC V24 model, Z94.84 maps to Major Organ Transplant or Replacement Status (HCC 186) with a community, non-dual, aged base RAF weight of 0.910. 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 to document stem cell transplant status for ongoing medical management. Because Z94.84 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 Z94.84 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code to document stem cell transplant status for ongoing medical management
- •May be used in conjunction with codes for the underlying condition being treated
Clinical Significance
This code represents successful stem cell transplantation with engraftment, indicating survival from severe hematologic or oncologic conditions requiring complex immunosuppressive therapy and ongoing monitoring. These patients have high risk for graft-versus-host disease, infection, and secondary malignancies.
Documentation Requirements
- ✓Confirmation of successful stem cell engraftment
- ✓Type of transplant (autologous vs allogeneic)
- ✓Source of stem cells (peripheral blood, cord blood)
- ✓Date of transplant if available
- ✓Current hematologic recovery status
- ✓Immunosuppressive regimen if allogeneic
- ✓Monitoring for GVHD and complications
- ✓Oncology/hematology follow-up care