Z23 ICD-10-CM Code: Encounter for immunization

A clear reference for the official code description, hierarchy, and related coding information from the FY 2027 U.S. release.

Official description

Z23

Encounter for immunization

ICD-10-CM diagnosis code · United States clinical modification

Where Z23 sits

  1. 1

    Chapter 21

    Factors influencing health status and contact with health services (Z00-Z99)

  2. 2

    Section

    Persons with potential health hazards related to communicable diseases (Z20-Z29)

  3. 3

    Category Z23

    Encounter for immunization

  4. 4

    Code Z23

    Encounter for immunization

Notes for this code

Inclusion terms

No inclusion terms are listed for Z23.

Code first

  • any routine childhood examination

Use additional code

No “use additional code” instruction is listed for Z23.

Excludes1

Conditions that should not be reported together with this code.

No Excludes1 note is listed for Z23.

Excludes2

Conditions not included here that may be reported separately when present.

No Excludes2 note is listed for Z23.

Source and release

Data release
U.S. ICD-10-CM · FY 2027
Effective date
Oct 1, 2026

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 Z23 mean?

Z23 is the FY 2027 U.S. ICD-10-CM code for “Encounter for immunization.”

Is Z23 a billable or specific ICD-10-CM code?

Yes. In the FY 2027 reference data used on this page, Z23 has no child codes and is presented as a billable/specific code. Always confirm the active code set and payer requirements before use.

Where is Z23 located in ICD-10-CM?

Z23 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 Z23, Encounter for immunization.

What coding notes are listed for Z23?

No inclusion terms are listed for Z23 in this reference record. Code-first instructions: any routine childhood examination. No Excludes1 note is listed. No Excludes2 note is listed.