Z23
Encounter for immunization
Z23 is a billable ICD-10-CM diagnosis code for encounter for immunization. It is part of the FY2027 code set, effective October 1, 2026. The Alphabetic Index lists it under 4 entries. Its coding notes include a Code first instruction and a Code also instruction.
Guidelines tip
From the FY2027 Official Guidelines. ICD10Ref adds no rules of its own.
Z23 can be a secondary code when the inoculation is given as part of routine preventive care. Procedure codes identify the administration and the immunizations given.
Code first
If the underlying condition listed here is present and known, sequence it first.
- any routine childhood examination
Code also
Two codes may be needed to describe the condition. This note gives no sequencing order.
- , if applicable, encounter for immunization safety counseling (Z71.85)
Notes
- procedure codes are required to identify the types of immunizations given
Also from chapter/block level (3 notes)
- Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
- (a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
- (b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.
Alphabetic Index terms
Terms the official Alphabetic Index lists for this code. 4 entries