T86.859
BillableUnspecified complication of intestine transplant
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is T86.859 an HCC code?
Yes. T86.859 maps to Intestine Transplant Status/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 T86.859
For T86.859 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 T86.859 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
T86.859 is the ICD-10-CM diagnosis code for unspecified complication of intestine transplant. An unspecified problem or complication that occurs after a patient receives a transplanted intestine, where the specific type of complication is not identified. T86.859 sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering complications of surgical and medical care, not elsewhere classified (t80-t88).
Under the CMS-HCC V28 risk adjustment model, T86.859 maps to Intestine Transplant Status/Complications (HCC 77) with a community, non-dual, aged base RAF weight of 0.000. Under the older CMS-HCC V24 model, T86.859 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 only when the specific complication (rejection, failure, infection) is not documented; query the provider for more specificity. Because T86.859 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 T86.859 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Use this code only when the specific complication (rejection, failure, infection) is not documented; query the provider for more specificity
- •Review transplant records and clinical notes to determine if a more specific T86.8x code applies
Clinical Significance
Unspecified intestinal transplant complication indicates a documented transplant-related problem without specific identification. Despite lack of specificity, this represents significant risk requiring ongoing specialized monitoring and care.
Documentation Requirements
- ✓Documentation of intestinal transplant procedure
- ✓Evidence of transplant-related complication without specific type
- ✓Clinical findings suggesting complication presence
- ✓Provider acknowledgment of complication
- ✓Treatment or monitoring plans
- ✓Exclusion of normal post-transplant status
- ✓Rationale for unspecified nature
- ✓Plans for further evaluation if appropriate