Alphabetic Index FY2027

Z28

Immunization not carried out and underimmunization status

FY2027Chapter 21: Factors influencing health status and contact with health services/Z20–Z29 Persons with potential health hazards related to communicable diseases

Non-billable headerNot valid on its own. Use one of the more specific codes under it.

Z28 is a non-billable ICD-10-CM code category for immunization not carried out and underimmunization status. Report a more specific code from it instead. It is part of the FY2027 code set, effective October 1, 2026. The more specific codes under it are Z28.0 Immunization not carried out because of contraindication, Z28.1 Immunization not carried out because of patient decision for reasons of belief or group pressure, Z28.2 Immunization not carried out because of patient decision for other and unspecified reason, Z28.3 Underimmunization status and 2 more. Its coding notes include a Code also instruction.

Code also

Two codes may be needed to describe the condition. This note gives no sequencing order.

This code
  • , if applicable, encounter for immunization safety counseling (Z71.85)

Includes

Further defines or gives examples of the content of the category.

This code
  • vaccination not carried out

Notes

Also from chapter/block level (3 notes)
Inherited from Chapter 21 Factors influencing health status and contact with health services
  • Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
    • (a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
    • (b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.

More specific codes under Z28 6