S98.929A ICD-10-CM Code: Partial traumatic amputation of unspecified foot, level unspecified, initial encounter

S98.929A is the ICD-10-CM diagnosis code for partial traumatic amputation of unspecified foot, level unspecified, initial encounter. S98.929A sits in the ICD-10-CM chapter for injury, poisoning and certain other consequences of external causes (s00-t88), within the section covering injuries to the ankle and foot (s90-s99).

Under the CMS-HCC V28 risk adjustment model, S98.929A maps to Traumatic Amputations and Complications (HCC 405) with a source-labeled community, non-dual, aged reference coefficient of 0.598. No V24 mapping is shown for S98.929A; use the applicable model and payment year when reviewing the V28 mapping. For CY2026 non-PACE Medicare Advantage, CMS uses 100% of the 2024 CMS-HCC model (V28). PACE uses a separate model blend. Source-labeled code-level coefficients are references, not member totals. Actual contribution depends on complete member context, hierarchy and cleanup rules, interactions, and model year. HCC Buddy's RAF Calculator supports CMS-HCC V28 PY2026 and shows no score unless every required source and calculation check passes.

Coders should report S98.929A only when the provider documentation supports the specific condition described, since more specific codes within the same hierarchy can capture additional clinical detail. For S98.929A, confirm that the documentation supports the diagnosis and meets the applicable coding, encounter, program and payer requirements. MEAT (Monitor, Evaluate, Assess, or Treat) is a review mnemonic, not a universal CMS coding rule. When documentation is ambiguous, coders should issue a provider query rather than assume the highest-specificity variant.