Non-Billable / Non-Specific Code
ICD-10-CM Z28 is the diagnosis code for Immunization not carried out and underimmunization status. This code falls under the section "Persons with potential health hazards related to communicable diseases" within Chapter 21 — Factors influencing health status and contact with health services (Z00-Z99). It is a non-billable/non-specific ICD-10-CM code that should not be used for reimbursement. A more specific sub-code is required for billing. Medical coders and healthcare providers use this code to document and classify diagnoses in electronic health records, insurance claims, and clinical databases.
Always refer to the official ICD-10-CM Tabular List for complete coding guidelines. Ensure documentation supports the specificity of the code selected. When in doubt, consult a certified medical coder or the latest CMS guidelines.
Understanding where Z28 sits in the ICD-10-CM classification helps ensure proper coding:
No, Z28 is a non-billable/non-specific code. You should use a more specific sub-code for billing and reimbursement.
Z28 is the ICD-10-CM diagnosis code for "Immunization not carried out and underimmunization status". It is used by healthcare providers to classify and document this condition in medical records and insurance claims.
Z28 is located in Section Z20-Z29 — "Persons with potential health hazards related to communicable diseases" within Chapter 21 of the ICD-10-CM Tabular List.
Z28 has 6 sub-code(s) that provide more specific detail: Z28.0, Z28.1, Z28.2, Z28.3, Z28.8 and more.
Use Z28 when the patients documented diagnosis matches "Immunization not carried out and underimmunization status" and the clinical documentation supports this level of specificity. Always verify with the latest ICD-10-CM guidelines and payer requirements.
The ICD-10-CM code for Immunization not carried out and underimmunization status is Z28.
No, Z28 is non-billable. Use a more specific sub-code for primary diagnosis billing.
Z28 is in Chapter 21 of the ICD-10-CM Tabular List.
Yes, Z28 is a valid ICD-10-CM code for the 2026 fiscal year, subject to official CMS updates.