Underimmunization status

Not billableICD-10-CM diagnosis code.

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

Billable FY2016 to FY2022, and a category header from FY2023.

Submit one of these 2 more specific codes instead:

Z28.31 Underimmunization for COVID-19 status (also a header)
Z28.39 Other underimmunization status

Use instead:

Z28.310 Unvaccinated for COVID-19 stated for FY2022
Z28.311 Partially vaccinated for COVID-19 stated for FY2022

What has happened to this code

Every change the publisher made, from 2010 to now. Entries marked draft are from the pre-implementation releases: ICD-10 took effect on 1 October 2015, so nothing before FY2016 was ever valid on a claim.

FY2010 Added to the draft code set draft Underimmunization status
FY2022 Stopped being billable

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

Codes in the same group

Code	Description	Status
Z28.0	Immunization not carried out because of contraindication	Not billable
Z28.1	Immunization not carried out because of patient decision for reasons of belief or group pressure	Valid
Z28.2	Immunization not carried out because of patient decision for other and unspecified reason	Not billable
Z28.8	Immunization not carried out for other reason	Not billable
Z28.9	Immunization not carried out for unspecified reason	Valid