Z28
Immunization not carried out and underimmunization status
Not billable — category only FY2026 2025-10-01 → 2026-09-30
Instructional notes 5
Z28code
Z00-Z99chapter
Notes
- 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:Z00-Z99A00-Y89
- (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.
Index entries leading here filed at null
No alphabetic index entry points at this code.
Subordinate codes 6
Z28.0 Immunization not carried out because of contraindication Z28.1 Immuniz not crd out because of patient belief/grp pressr Z28.2 Immuniz not crd out bec pt decision for oth and unsp reason Z28.3 Underimmunization status Z28.8 Immunization not carried out for other reason Z28.9 Immunization not carried out for unspecified reason
Additional references
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Official coding advice for this code. Published by the American Hospital Association. Not included in this installation.