The ICD-10-CM tabular list includes a code first instruction under code Z23 that instructs to code first any routine childhood examination. This indicates that Z23 is not the first-listed code when provided in conjunction with a routine child health examination.
The tabular list also includes the following inclusion terms under Z00.12 Encounter for routine child health examination:
Health check (routine) for child over 28 days old
Immunizations appropriate for age
Routine developmental screening of infant or child
Routine vision and hearing testing
The ICD-10-CM guidelines also support reporting both the Z00.12- code and Z23 with the instruction, "Code Z23 may be used as a secondary code if the inoculation is given as a routine part of preventive health care, such as a well-baby visit."
I hope this is helpful.
Cindy