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  6. 2026 ICD-10-CM Code Z28

2026 ICD-10-CM Diagnosis Code Z28

Immunization not carried out and underimmunization status

ICD-10-CM Code:
Z28
ICD-10 Code for:
Immunization not carried out and underimmunization status
Is Billable?
Not Valid for Submission
Code Navigator:

Z28 is a non-specific and non-billable diagnosis code code, consider using a code with a higher level of specificity from the list below for a diagnosis of immunization not carried out and underimmunization status. The code is not specific and is NOT valid for the year 2026 for the submission of HIPAA-covered transactions. Category or Header define the heading of a category of codes that may be further subdivided by the use of 4th, 5th, 6th or 7th characters.

Specific Coding Applicable to Immunization not carried out and underimmunization status

Non-specific codes like Z28 require more digits to indicate the appropriate level of specificity. Consider using any of the following billable codes with a higher level of specificity when coding for immunization not carried out and underimmunization status:

  • Z28.0 for Immunization not carried out because of contraindication

  • Use Z28.01 for Immunization not carried out because of acute illness of patient

  • Use Z28.02 for Immunization not carried out because of chronic illness or condition of patient

  • Use Z28.03 for Immunization not carried out because of immune compromised state of patient

  • Use Z28.04 for Immunization not carried out because of patient allergy to vaccine or component

  • Use Z28.09 for Immunization not carried out because of other contraindication

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

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

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

  • Use Z28.21 for Immunization not carried out because of patient refusal

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

  • Z28.3 for Underimmunization status

  • Z28.31 for Underimmunization for COVID-19 status

  • Use Z28.39 for Other underimmunization status

  • Z28.8 for Immunization not carried out for other reason

  • Use Z28.81 for Immunization not carried out due to patient having had the disease

  • Use Z28.82 for Immunization not carried out because of caregiver refusal

  • Use Z28.83 for Immunization not carried out due to unavailability of vaccine

  • Use Z28.89 for Immunization not carried out for other reason

  • Use Z28.9 for Immunization not carried out for unspecified reason

Code Classification

  • Factors influencing health status and contact with health services
    Z00–Z99
    • Persons with potential health hazards related to communicable diseases
      Z20-Z29
      • Immunization not carried out and underimmunization status
        Z28

Tabular List of Diseases and Injuries

The following annotation back-references are applicable to this diagnosis code. The Tabular List of Diseases and Injuries is a list of ICD-10-CM codes, organized "head to toe" into chapters and sections with coding notes and guidance for inclusions, exclusions, descriptions and more.


Includes

Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
  • vaccination not carried out

Code Also

Code Also
A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.
  • , if applicable, encounter for immunization safety counseling Z71.85

Code History

  • FY 2026 - No Change, effective from 10/1/2025 through 9/30/2026
  • FY 2025 - No Change, effective from 10/1/2024 through 9/30/2025
  • FY 2024 - No Change, effective from 10/1/2023 through 9/30/2024
  • FY 2023 - No Change, effective from 10/1/2022 through 9/30/2023
  • FY 2022 - No Change, effective from 10/1/2021 through 9/30/2022
  • FY 2021 - No Change, effective from 10/1/2020 through 9/30/2021
  • FY 2020 - No Change, effective from 10/1/2019 through 9/30/2020
  • FY 2019 - No Change, effective from 10/1/2018 through 9/30/2019
  • FY 2018 - No Change, effective from 10/1/2017 through 9/30/2018
  • FY 2017 - No Change, effective from 10/1/2016 through 9/30/2017
  • FY 2016 - New Code, effective from 10/1/2015 through 9/30/2016. This was the first year ICD-10-CM was implemented into the HIPAA code set.