Z91.A18
BillableCaregiver's noncompliance with patient's dietary regimen for other reason
Last updated: FY2026 ICD-10-CM (Oct 1, 2025 – Sep 30, 2026) | CMS-HCC V28 (100% phase-in, PY2026)
Is Z91.A18 an HCC code?
No. Z91.A18 is a billable ICD-10-CM code but does not map to any HCC category in V28, V24, ESRD, or RxHCC.
This code does not map to an HCC category in any model (V28, V24, ESRD, RxHCC).
What This Code Means
Z91.A18 is the ICD-10-CM diagnosis code for caregiver's noncompliance with patient's dietary regimen for other reason. A caregiver is not following the patient's prescribed diet for reasons other than financial hardship, such as lack of knowledge or disagreement with the regimen. Z91.A18 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).
Z91.A18 is a billable ICD-10-CM code but does not map to a payment HCC under the CMS-HCC V28, V24, ESRD, or RxHCC risk adjustment models. It can be reported on Medicare Advantage encounter data submissions but it does not contribute to a beneficiary's RAF score and therefore does not affect risk-adjusted payments to the plan.
Document the specific reason for noncompliance in the medical record when using this code.
HCC Buddy maintains structured V28 and V24 mapping, RAF weights, and MEAT documentation criteria for Z91.A18 sourced directly from the CMS-HCC risk adjustment model files and the CMS ICD-10-CM code set.
Coding Tips
- •Document the specific reason for noncompliance in the medical record when using this code.
- •Use this code when the reason for dietary noncompliance is not financial hardship.