1. Home
2. ICD-10 Codes
3. Chapter - Z00-Z99
4. Section - Z20-Z29
5. Category - Z28
6. Z28.31

Z28.31 - Underimmunization for COVID-19 status

• Applicable to Underimmunization for COVID-19 status
• The 2025 edition of ICD10-CM Z28.31 became effective on October 1, 2024.
• This is the American ICD10-CM version of Z28.31 - other international versions of ICD10 Z28.31 may differ.
• Z28.31 is a Non-Billable / Non-Specific ICD10-CM code that can be used to indicate a diagnosis for reimbursement purposes.
• Z28.31 Code should not be used for billing or reimbursement purposes as there are multiple ICD-10 CM codes below it that contain a greater level of detail.

Code Notes:

• These codes should not be used for individuals who are not eligible for the COVID-19 vaccines, as determined by the healthcare provider.

The following codes above Z28.31 contain annotation back-references that may be applicable to Z28.31:

• Chapter: Z00-Z99 - Factors influencing health status and contact with health services
• Section: Z20-Z29 - Persons with potential health hazards related to communicable diseases
• Category: Z28 - Immunization not carried out and underimmunization status

Browse other similar CM codes:

Reimbursement claims with a date of service on or after October 1, 2015 require the use of ICD-10-CM codes.