1. Z28 Immunization not carried out and underimmunization status

    1. Z28.0 Immunization not carried out because of contraindication

      1. Z28.01 Immunization not carried out because of acute illness of patient

      2. Z28.02 Immunization not carried out because of chronic illness or condition of patient

      3. Z28.03 Immunization not carried out because of immune compromised state of patient

      4. Z28.04 Immunization not carried out because of patient allergy to vaccine or component

      5. Z28.09 Immunization not carried out because of other contraindication

    2. Z28.1 Immunization not carried out because of patient decision for reasons of belief or group pressure

      Inclusion term(s):

      • Immunization not carried out because of religious belief
    3. Z28.2 Immunization not carried out because of patient decision for other and unspecified reason

      1. Z28.20 Immunization not carried out because of patient decision for unspecified reason

      2. Z28.21 Immunization not carried out because of patient refusal

      3. Z28.29 Immunization not carried out because of patient decision for other reason

    4. Z28.3 Underimmunization status

      1. Z28.31 Underimmunization for COVID-19 status

        Note: These codes should not be used for individuals who are not eligible for the COVID-19 vaccines, as determined by the healthcare provider.

        • Z28.310 Unvaccinated for COVID-19
        • Z28.311 Partially vaccinated for COVID-19
      2. Z28.39 Other underimmunization status

        Inclusion term(s):

        • Delinquent immunization status
        • Lapsed immunization schedule status
    5. Z28.8 Immunization not carried out for other reason

      1. Z28.81 Immunization not carried out due to patient having had the disease

      2. Z28.82 Immunization not carried out because of caregiver refusal

        Inclusion term(s):

        • Immunization not carried out because of guardian refusal
        • Immunization not carried out because of parent refusal
      3. Z28.83 Immunization not carried out due to unavailability of vaccine

        Inclusion term(s):

        • Delay in delivery of vaccine
        • Lack of availability of vaccine
        • Manufacturer delay of vaccine
      4. Z28.89 Immunization not carried out for other reason

    6. Z28.9 Immunization not carried out for unspecified reason

Abbreviations used here:

NEC Not elsewhere classifiable
This abbreviation in the Tabular List represents “other specified”. When a specific code is not available for a condition, the Tabular List includes an NEC entry under a code to identify the code as the “other specified” code.

NOS Not otherwise specified
This abbreviation is the equivalent of unspecified.