Z23
✓ Billable
Encounter for immunization
ICD-10-CM · FY2026 · Factors Influencing Health Status
Code
Z23
System
ICD-10-CM
Billable
Yes — valid for submission
Effective
FY2026
Chapter
Factors Influencing Health Status
Source
CMS / CDC NCHS
⚠ Verify before billing. Confirm against the current CMS/NCHS ICD-10-CM files and your payer's rules before claims submission.
Frequently asked questions
What is ICD-10 code Z23?
ICD-10-CM code Z23 represents Encounter for immunization. It is a billable diagnosis code in the Factors Influencing Health Status chapter, effective October 1, 2025 – September 30, 2026.
Is Z23 billable?
Yes. Z23 is a valid billable ICD-10-CM code for insurance claims and clinical documentation.
What chapter is Z23 in?
Z23 belongs to the Factors Influencing Health Status chapter (Z00–Z99) of ICD-10-CM.
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