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Z91.A4

Z91.A4Caregiver's other noncompliance with patient's medication regimen

Non-billable headerICD-10-CM

Z91.A4 is a non-billable header ICD-10-CM code for caregiver's other noncompliance with patient's medication regimen. It cannot be billed on its own: choose one of the more specific child codes below.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Caregiver's underdosing of patient's medication NOS
  • Caregiver's underdosing with patient's medication NOS

Excludes2 inherited from the categories above Z91.A4

Also inherited, and the opposite of Excludes1: these conditions are not part of Z91.A4, but a patient can have both, so you may code both.

Written on Z91 Personal risk factors, not elsewhere classified

  • contact with and (suspected) exposures hazardous to health (Z77.-)
  • exposure to pollution and other problems related to physical environment (Z77.1-)
  • female genital mutilation status (N90.81-)
  • occupational exposure to risk factors (Z57.-)
  • personal history of physical injury and trauma (Z87.81, Z87.82-)

Risk adjustment

Z91.A4 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

Code history

Z91.A4 has not changed since FY2024 — no addition, revision or deletion across the three most recent ICD-10-CM releases.

Code to one of these instead Z91.A4

2 child codes. Green means billable.

Related codes at this level

Codes that share Z91.A. If Z91.A4 is not quite right, the correct code is usually one of these.

Questions about Z91.A4

Is Z91.A4 a billable ICD-10-CM code?
No. Z91.A4 is a non-billable header code. Code to a higher level of specificity using one of its child codes.
Where does Z91.A4 sit in the tabular list?
Factors influencing health status and contact with health services (Z00-Z99), in the block Persons with potential health hazards related to family and personal history and certain conditions influencing health status (Z77-Z99).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.