Z28 ICD-10-CM Code: Immunization not carried out and underimmunization status
A clear reference for the official code description, hierarchy, and related coding information from the FY 2027 U.S. release.
Official description
Z28Immunization not carried out and underimmunization status
ICD-10-CM diagnosis code · United States clinical modification
Where Z28 sits
- 1
Chapter 21
Factors influencing health status and contact with health services (Z00-Z99)
- 2
Section
Persons with potential health hazards related to communicable diseases (Z20-Z29)
- 3
Category Z28
Immunization not carried out and underimmunization status
- 4
Code Z28
Immunization not carried out and underimmunization status
Codes under Z28
Z28 is a non-billable category. Choose the child code that best matches the documented diagnosis.
Z28.0Immunization not carried out because of contraindicationZ28.1Immunization not carried out because of patient decision for reasons of belief or group pressureZ28.2Immunization not carried out because of patient decision for other and unspecified reasonZ28.3Underimmunization statusZ28.8Immunization not carried out for other reasonZ28.9Immunization not carried out for unspecified reasonNotes for this code
Inclusion terms
No inclusion terms are listed for Z28.
Code first
No “code first” instruction is listed for Z28.
Use additional code
No “use additional code” instruction is listed for Z28.
Excludes1
Conditions that should not be reported together with this code.
No Excludes1 note is listed for Z28.
Excludes2
Conditions not included here that may be reported separately when present.
No Excludes2 note is listed for Z28.
Source and release
- Data release
- U.S. ICD-10-CM · FY 2027
- Effective date
- Oct 1, 2026
- Publisher
- Vero Scribe Inc.
This reference is generated from Vero’s ICD-10-CM description, hierarchy, and code-note dataset. The visible content and structured data share that source.
Frequently asked questions
What does ICD-10-CM code Z28 mean?
Z28 is the FY 2027 U.S. ICD-10-CM code for “Immunization not carried out and underimmunization status.”
Is Z28 a billable or specific ICD-10-CM code?
No. Z28 has more specific child codes in the FY 2027 reference data. Select the code that matches the documentation and confirm the active code set and payer requirements.
Where is Z28 located in ICD-10-CM?
Z28 is listed in Chapter 21, Factors influencing health status and contact with health services (Z00-Z99), within Persons with potential health hazards related to communicable diseases (Z20-Z29) (Z20–Z29), under category Z28, Immunization not carried out and underimmunization status.
What coding notes are listed for Z28?
No inclusion terms are listed for Z28 in this reference record. No code-first instruction is listed. No Excludes1 note is listed. No Excludes2 note is listed.