Free Medical Coding > ICD10 CM > 2024 ICD-10-CM Codes > 2024 ICD-10-CM Codes Z00-Z99 – Factors influencing health status and contact with health services (Z00-Z99) > 2024 ICD-10-CM Codes Z20-Z29 – Persons with potential health hazards related to communicable diseases (Z20-Z29) > 2024 ICD-10-CM Codes Z28 – Immunization not carried out and underimmunization status (Z28) > 2024 ICD-10-CM Codes Z28.3 – Underimmunization status (Z28.3)