ICD-10 · PDGM grouping
Z28 Immunization not carried out and underimmunization status
All 17 codes in the Z28 family, with the PDGM clinical group, comorbidity subgroup and primary-position rule CMS assigns, read from the CMS grouper crosswalk v07.2.26 and the CDC FY2027 code file.
Codes in family
17
Can lead a claim
0
Cannot lead a claim
17
What CMS assigns to Z28
None of the 17 codes is assigned a clinical group. None of the 17 is assigned a comorbidity subgroup. None can lead a claim.
Every code in Z28
Descriptions are CDC’s FY2027 wording; where CMS’s grouper abbreviates one, its form is shown beneath.
| Code | Description | Primary position | Clinical group | Comorbidity subgroup |
|---|---|---|---|---|
| Z28.0 Immunization not carried out because of contraindication | ||||
| Z28.01 | Immunization not carried out because of acute illness of patientCMS: Immunization not crd out because of acute illness of patient | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.02 | Immunization not carried out because of chronic illness or condition of patientCMS: Immuniz not crd out bec chronic illness or cond of patient | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.03 | Immunization not carried out because of immune compromised state of patientCMS: Immuniz not crd out bec immune compromised state of patient | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.04 | Immunization not carried out because of patient allergy to vaccine or componentCMS: Immuniz not crd out bec patient allergy to vaccine or cmpnt | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.09 | Immunization not carried out because of other contraindicationCMS: Immunization not carried out because of oth contraindication | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.1 | Immunization not carried out because of patient decision for reasons of belief or group pressureCMS: Immuniz not crd out because of patient belief/grp pressr | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.2 Immunization not carried out because of patient decision for other and unspecified reason | ||||
| Z28.20 | Immunization not carried out because of patient decision for unspecified reasonCMS: Immuniz not crd out bec patient decision for unsp reason | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.21 | Immunization not carried out because of patient refusal | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.29 | Immunization not carried out because of patient decision for other reasonCMS: Immuniz not crd out bec patient decision for oth reason | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.3 Underimmunization status | ||||
| Z28.31 Underimmunization for COVID-19 status | ||||
| Z28.310 | Unvaccinated for COVID-19 | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | None |
| Z28.311 | Partially vaccinated for COVID-19 | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | None |
| Z28.39 | Other underimmunization status | Cannot lead a claimUnacceptable principal diagnosis, code is not reportable as principal diagnosis | None | None |
| Z28.8 Immunization not carried out for other reason | ||||
| Z28.81 | Immunization not carried out due to patient having had the diseaseCMS: Immuniz not crd out due to patient having had the disease | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.82 | Immunization not carried out because of caregiver refusal | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.83 | Immunization not carried out due to unavailability of vaccineCMS: Immunization not crd out due to unavailability of vaccine | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.89 | Immunization not carried out for other reason | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
| Z28.9 | Immunization not carried out for unspecified reason | Cannot lead a claimPrincipal diagnosis not assigned to a clinical group | None | None |
Sources: CMS HH PPS Grouper Software v07.2.26, effective 2026-10-01, for the clinical group, comorbidity subgroup, code-first conventions and primary-position flags; CDC NCHS ICD-10-CM FY2027 code descriptions for the family title and code wording. This is the crosswalk Medicare runs a claim through. Grouping also depends on admission source, timing, the OASIS functional items and the rest of the diagnosis list.
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