ICD-10-CM › Z00-Z99 › Z20-Z29 › Z28.3 Underimmunization status › Z28.31

This code exists but cannot be submitted on its own. It groups the more specific codes beneath it.

A category header for its whole life, FY2022 onwards. It has never been valid for submission on its own.

Submit one of these 2 more specific codes instead:

• Z28.310 Unvaccinated for COVID-19
• Z28.311 Partially vaccinated for COVID-19

What has happened to this code

Official coding rules

Published by CDC for FY2027. A rule attached to a category binds every code beneath it, so the rules inherited from this code's ancestors are shown with the code they come from.

Inherited from Z28 Immunization not carried out and underimmunization status

Code also

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

Includes

• vaccination not carried out

How CDC's index refers to this code

Wording from the official alphabetic index. Much of it appears nowhere in the code description, which is why a search for the everyday phrase so often finds nothing.

• Inoculation
• Unimmunized
• Immunization
• Unvaccinated
• Need > vaccination
• Postsurgery status
• Need > immunization
• Vaccination > partial
• Immunization > partial
• Vaccination > not done
• Immunization > not done
• Underimmunization status > COVID-19
• Status > underimmunization > COVID-19
• Delinquent immunization status > COVID-19
• Status > delinquent immunization > COVID-19

Codes in the same group

Code	Description	Status
Z28.39	Other underimmunization status	Valid