T86.810
BillableLung transplant rejection
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is T86.810 an HCC code?
Yes. T86.810 maps to Lung 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 T86.810
For T86.810 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 T86.810 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
T86.810 is the ICD-10-CM diagnosis code for lung transplant rejection. The recipient's immune system attacks and rejects the transplanted lung tissue after a lung transplant procedure. T86.810 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, T86.810 maps to Lung Transplant Status/Complications (HCC 276) with a community, non-dual, aged base RAF weight of 0.193. Under the older CMS-HCC V24 model, T86.810 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.
Document the timeframe of rejection (acute vs. chronic) as this may affect clinical management and coding specificity. Because T86.810 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 T86.810 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the timeframe of rejection (acute vs. chronic) as this may affect clinical management and coding specificity
- •Ensure documentation distinguishes lung transplant rejection from other lung transplant complications
Clinical Significance
Lung transplant rejection represents a serious immunological complication requiring immediate intervention and adjustment of immunosuppressive therapy. This condition significantly impacts patient survival and quality of life, making it a critical diagnosis for risk stratification and care planning.
Documentation Requirements
- ✓Clear documentation of prior lung transplant procedure with date
- ✓Clinical evidence of rejection (biopsy results, imaging findings, pulmonary function decline)
- ✓Immunosuppressive medication history and current regimen
- ✓Symptoms consistent with rejection (dyspnea, cough, fever, decreased exercise tolerance)
- ✓Laboratory values supporting rejection (arterial blood gases, inflammatory markers)
- ✓Physician statement confirming rejection diagnosis
- ✓Differentiation from infection or other complications
- ✓Treatment plan for rejection management
Commonly Confused Codes
- •T86.811 — lung transplant failure (functional failure vs immunologic rejection)
- •T86.812 — lung transplant infection (infectious vs immunologic complication)
- •Z94.2 — lung transplant status without complications (status vs active complication)
- •J44.1 — COPD with acute exacerbation (native lung disease vs transplant complication)
- •T86.818 — other lung transplant complications (specific rejection vs other complications)