Z28 is a non-billable/non-specific diagnosis code from the 2025 ICD-10-CM used to classify the following condition: Immunization not carried out and underimmunization status.
Includes
- Vaccination not carried out 
Code also
- If applicable, encounter for immunization safety counseling (Z71.85) 
Codes
- 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 
- Z28.8- Immunization not carried out for other reason 
- Z28.9- Immunization not carried out for unspecified reason 
Versions
- 2025- No changes 
- 2024- No changes 
- 2023- No changes 
- 2022- Code changed - Code also- , if applicable, encounter for immunization safety counseling (Z71.85)
 
 
 
- 2021- No changes 
- 2020- No changes 
- 2019- No changes 
- 2018- No changes 
- 2017- No changes 
- 2016- New code