Z44.109
BillableEncounter for fitting and adjustment of unspecified artificial leg, unspecified leg
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Z44.109 an HCC code?
Yes. Z44.109 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 Z44.109
For Z44.109to 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 Z44.109 during that encounter — not just copy-forwarded from a problem list.
What This Code Means
Z44.109 is the ICD-10-CM diagnosis code for encounter for fitting and adjustment of unspecified artificial leg, unspecified leg. A patient visit to have an artificial leg (prosthetic) of unspecified type fitted or adjusted when the specific side is not documented or is bilateral. Z44.109 sits in the ICD-10-CM chapter for factors influencing health status and contact with health services (z00-z99), within the section covering encounters for other specific health care (z40-z53).
Under the CMS-HCC V28 risk adjustment model, Z44.109 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 Z44.109 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.
This is the least specific code for leg prosthetic fitting; use only when both laterality and prosthetic type are unclear. Because Z44.109 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 Z44.109 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •This is the least specific code for leg prosthetic fitting; use only when both laterality and prosthetic type are unclear
- •Always attempt to obtain more specific information from the medical record or provider
Clinical Significance
This code indicates a patient has undergone lower limb amputation requiring prosthetic management when laterality is not specified or is bilateral. The encounter demonstrates significant functional impairment and ongoing specialized care needs for prosthetic management.
Documentation Requirements
- ✓Documentation of encounter purpose for prosthetic fitting or adjustment
- ✓Clear indication this is an artificial leg prosthetic service
- ✓Type of prosthetic service provided (fitting, adjustment, repair)
- ✓Patient's underlying amputation status or history
- ✓Reason why laterality is unspecified or if bilateral amputation
- ✓Functional assessment or prosthetic needs evaluation
- ✓Provider specialty or clinic type performing the service
- ✓Any complications or issues with current prosthesis
Commonly Confused Codes
- •Z44.119 — Use when documentation specifies complete artificial leg rather than unspecified type
- •Z44.129 — Use when documentation specifies partial artificial leg rather than unspecified type
- •Z44.101/Z44.102 — Use when laterality is clearly documented as right or left
- •Z44.00- series — These are for artificial arm prosthetics, not leg prosthetics
- •Z89.- codes — These are for acquired absence of limb, not prosthetic encounters