Z91.A3 – Caregiver's unintentional underdosing of patient's medication regimen

ICD-10-CM 2027 diagnosis code · Persons with potential health hazards related to family and personal history and certain conditions influencing health status

Billable code

ICD-10-CM code Z91.A3
Code
Z91.A3 (claims format: Z91A3)
Description
Caregiver's unintentional underdosing of patient's medication regimen
Short description
Carers unintent underdosing of patient's medication regimen
Billable
Yes – valid for HIPAA-covered transactions
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
21. Factors influencing health status and contact with health services (Z00-Z99)
Block
Z77-Z99 Persons with potential health hazards related to family and personal history and certain conditions influencing health status
Parent codes
Z91 › Z91.A

Notes for Z91.A3

Code first:
  • underdosing of medication (T36-T50) with fifth or sixth character 6

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Z91 – Personal risk factors, not elsewhere classified

Excludes2 (not included here):
  • 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-)

Block Z77-Z99

Code also:
  • any follow-up examination (Z08-Z09)

Index terms for Z91.A3

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in Z91.A

Frequently asked questions

What is ICD-10 code Z91.A3?

Z91.A3 is the ICD-10-CM code for caregiver's unintentional underdosing of patient's medication regimen, in the block Z77-Z99 (Persons with potential health hazards related to family and personal history and certain conditions influencing health status).

Is Z91.A3 a billable code?

Yes. Z91.A3 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does Z91.A3 belong to?

It belongs to category Z91 – Personal risk factors, not elsewhere classified.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.