T81.502S ICD-10-CM Code: Unspecified complication of foreign body accidentally left in body following kidney dialysis, sequela

T81.502S is the ICD-10-CM diagnosis code for unspecified complication of foreign body accidentally left in body following kidney dialysis, sequela. T81.502S 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 older CMS-HCC V24 model, T81.502S maps to Dialysis Status (HCC 134) with a community, non-dual, aged base RAF weight of 0.452. 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.

Coders should report T81.502S only when the provider documentation supports the specific condition described, since more specific codes within the same hierarchy can capture additional clinical detail and may carry a higher RAF weight. Because T81.502S 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.