D89.813
BillableGraft-versus-host disease, unspecified
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is D89.813 an HCC code?
Yes. D89.813 maps to Graft-Versus-Host Disease and Stem Cell Transplant Complications under the CMS-HCC V28 risk adjustment model (and Disorders of Immunity 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 D89.813
For D89.813 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 D89.813 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
D89.813 is the ICD-10-CM diagnosis code for graft-versus-host disease, unspecified. A condition where immune cells from a donor attack the recipient's body after a bone marrow or stem cell transplant, but the specific type or severity is not documented. D89.813 sits in the ICD-10-CM chapter for diseases of the blood and blood-forming organs and certain disorders involving the immune mechanism (d50-d89), within the section covering certain disorders involving the immune mechanism (d80-d89).
Under the CMS-HCC V28 risk adjustment model, D89.813 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, D89.813 maps to Disorders of Immunity (HCC 47) with a community, non-dual, aged base RAF weight of 0.472. 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.
Query the provider for more specificity regarding the organ(s) involved (skin, GI tract, liver, etc.) as there are more specific codes available. Because D89.813 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 D89.813 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Query the provider for more specificity regarding the organ(s) involved (skin, GI tract, liver, etc.) as there are more specific codes available
- •This code should only be used when the type of GVHD cannot be determined from the medical record
Clinical Significance
Graft-versus-host disease, unspecified, is used when the provider documents graft-versus-host disease without specifying whether the presentation is acute, chronic, or overlap. While this code captures the condition, it lacks the clinical specificity needed for optimal risk stratification and clinical communication. It most commonly appears in initial encounters before full clinical characterization.
Documentation Requirements
- ✓While this code technically requires only a documented diagnosis of graft-versus-host disease following transplantation, best practice calls for the provider to specify acute versus chronic presentation.
- ✓Documentation should include the temporal relationship to transplant, affected organ systems, severity, and current treatment.
- ✓Query the provider to classify as acute (D89.810), chronic (D89.811), or overlap (D89.812) whenever possible.