Z89.432
BillableAcquired absence of left foot
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Z89.432 an HCC code?
Yes. Z89.432 maps to Amputation Status, Lower Limb/Amputation Complications under the CMS-HCC V28 risk adjustment model (and Amputation Status, Lower Limb/Amputation Complications 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 Z89.432
For Z89.432 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 Z89.432 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
Z89.432 is the ICD-10-CM diagnosis code for acquired absence of left foot. A person is missing their entire left foot due to amputation, injury, or surgical removal that occurred after birth. Z89.432 sits in the ICD-10-CM chapter for factors influencing health status and contact with health services (z00-z99), within the section covering persons with potential health hazards related to family and personal history and certain conditions influencing health status (z77-z99).
Under the CMS-HCC V28 risk adjustment model, Z89.432 maps to Amputation Status, Lower Limb/Amputation Complications (HCC 409) with a community, non-dual, aged base RAF weight of 0.350. The V24 model used during the PY2024–PY2025 transition mapped Z89.432 the same way and at the same RAF weight. 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.
Confirm complete foot absence versus partial foot amputation to ensure correct code selection. Because Z89.432 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 Z89.432 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Confirm complete foot absence versus partial foot amputation to ensure correct code selection.
- •Consider documenting the cause of amputation (trauma, diabetes, infection, etc.) in addition to this status code for complete clinical documentation.
Clinical Significance
Acquired absence of left foot represents a major lower extremity amputation causing severe mobility impairment and functional disability. This condition reflects significant underlying disease progression and requires extensive rehabilitation, prosthetic services, and ongoing specialized care management.
Documentation Requirements
- ✓Complete absence of left foot documented
- ✓Acquired nature of amputation specified
- ✓Anatomical level of amputation detailed
- ✓Underlying etiology or medical necessity
- ✓Current prosthetic device and functionality
- ✓Mobility status and ambulatory capacity
- ✓Ongoing rehabilitation needs and progress
- ✓Complication monitoring and management