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Y65.0

Billable

Mismatched blood in transfusion

Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)

Is Y65.0 an HCC code?

No. Y65.0 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.

This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).

What This Code Means

Y65.0 is the ICD-10-CM diagnosis code for mismatched blood in transfusion. A patient received blood of the wrong type during a transfusion, which can cause a serious immune reaction. Y65.0 sits in the ICD-10-CM chapter for external causes of morbidity (v00-y99), within the section covering misadventures to patients during surgical and medical care (y62-y69).

Y65.0 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.

Document both the blood type transfused and the patient's actual blood type.

HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Y65.0 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.

Coding Tips

  • Document both the blood type transfused and the patient's actual blood type
  • This is a critical patient safety event; ensure documentation of any hemolytic reaction or complications

Code Hierarchy

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