Z89.511 ICD-10-CM Code: Acquired absence of right leg below knee
Z89.511 maps to CMS-HCC V28 409 (RAF 0.598). Documentation must support MEAT. MEAT criteria · RAF calculator · HCC coding software
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FY 2026 Apr update / Factors influencing health status and contact with health services (Z00-Z99) / Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99)
Z89.511
Billable / SpecificICD-10-CMOfficial ICD-10-CMCodebook guidanceAcquired absence of right leg below knee
A person is missing part or all of their right leg below the knee due to amputation, injury, or surgical removal that occurred after birth.
Buddy Insight
Acquired absence of right leg below knee represents a major lower extremity amputation causing significant mobility impairment and functional disability.
CMS-HCC V28
MappedHCC 409
RAF 0.598
CMS-HCC V24
MappedHCC 189
RAF 0.519
ACA/HHS
MappedHCC 254
Varies by metal level
ESRD/PACE
MappedHCC 189
RAF 0.081
RXHCC
N/A—
Not mapped
Code Book Path
Inclusion Terms
OfficialICD-10-CM does not list inclusion terms for Z89.511 in this effective period.
Excludes 2
OfficialICD-10-CM does not list Excludes 2 notes for Z89.511 in this effective period.
Related Child Codes
Includes
OfficialICD-10-CM does not list Includes notes for Z89.511 in this effective period.
Excludes 1
OfficialICD-10-CM does not list Excludes 1 notes for Z89.511 in this effective period.
Code First
OfficialICD-10-CM does not list Code First sequencing instructions for Z89.511 in this effective period.
Use Additional
OfficialICD-10-CM does not list Use Additional Code instructions for Z89.511 in this effective period.
Code Also
OfficialICD-10-CM does not list Code Also instructions for Z89.511 in this effective period.
Buddy Documentation Tip
MEAT Support
Audit Caution
Common Mistakes
Current with CMS: FY2026 ICD-10-CM Apr 1 update (effective Apr 1 – Sep 30, 2026) · CMS-HCC V28, 100% phased in for payment year 2026. FY2027 code set already staged for October 1, 2026. How HCC Buddy stays current →
Is Z89.511 an HCC code?
Yes. Z89.511 (Acquired absence of right leg below knee) 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), with a community non-dual aged RAF of 0.598. It is billable for payment year 2026.
Coder answer: Z89.511 is billable and maps to V28 HCC 409, Amputation Status, Lower Limb/Amputation Complications. Open it in the Code Book for the tabular path, RAF, and MEAT checklist.
- Code
- Z89.511
- Description
- Acquired absence of right leg below knee
- HCC (V28)
- HCC 409 — Amputation Status, Lower Limb/Amputation Complications
- RAF
- 0.598
- Billable
- Yes
- Payment year
- 2026
HCC Category Mapping
Each model's RAF is its CMS base weight for that model's standard population, so weights are not directly comparable across models: CMS-HCC V28 and V24 use Community, Non-Dual, Aged; ESRD uses the dialysis continuing-enrollee model; RxHCC is the Part D continuing-enrollee, non-low-income, aged weight (a larger scale than CMS-HCC). ACA/HHS has no single weight — it varies by metal level. 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.
Work Z89.511 in the Code Book — tabular path, V28 RAF, and MEAT checklist →
MEAT Criteria for Z89.511
For Z89.511 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 Z89.511 during that encounter, not just copy-forwarded from a problem list.
Coder workflow notes
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What This Code Means
Z89.511 is the ICD-10-CM diagnosis code for acquired absence of right leg below knee. A person is missing part or all of their right leg below the knee due to amputation, injury, or surgical removal that occurred after birth. Z89.511 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, Z89.511 maps to Amputation Status, Lower Limb/Amputation Complications (HCC 409) with a community, non-dual, aged base RAF weight of 0.598. Under the older V24 model, Z89.511 mapped to the same category but with a base RAF weight of 0.519, V28 recalibrated weights across the entire model. 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.
Acquired absence of right leg below knee, BKA on the right side. The most common major lower-extremity amputation in diabetic vasculopathy. Because Z89.511 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 Z89.511 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Acquired absence of right leg below knee, BKA on the right side. The most common major lower-extremity amputation in diabetic vasculopathy.
- •Distinct from Z89.611 (AKA, above-knee amputation right). Amputation level drives prosthetic planning and coding.
- •V28 HCC 409 at RAF 0.598.
Clinical Significance
Acquired absence of right leg below knee represents a major lower extremity amputation causing significant mobility impairment and functional disability. This transtibial amputation typically results from severe vascular disease, trauma, or diabetic complications requiring extensive prosthetic rehabilitation and ongoing specialized care.
Documentation Requirements
- ✓Below-knee level amputation of right leg documented
- ✓Acquired nature of amputation specified
- ✓Anatomical level below knee joint confirmed
- ✓Underlying cause or medical indication
- ✓Length of residual limb documented
- ✓Current prosthetic device and fitting status
- ✓Functional mobility and independence level
- ✓Ongoing rehabilitation and therapy needs