ICD-10-CM
ICD-10 code for Unimmunized for COVID-19: Z28.310
The ICD-10-CM index points "Unimmunized for COVID-19" to Z28.310, Unvaccinated for COVID-19. Z28.310 is a billable code.
Source: CDC ICD-10-CM FY2027 Alphabetic Index file dated June 16, 2026. Publisher page
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More specific codes in Z28
A header groups codes and is not billed. A billable code is one you can report.
- Z28Immunization not carried out and underimmunization statusHeader
- Z28.0Immunization not carried out because of contraindicationHeader
- Z28.01Immunization not carried out because of acute illness of patientBillable
- Z28.02Immunization not carried out because of chronic illness or condition of patientBillable
- Z28.03Immunization not carried out because of immune compromised state of patientBillable
- Z28.04Immunization not carried out because of patient allergy to vaccine or componentBillable
- Z28.09Immunization not carried out because of other contraindicationBillable
- Z28.1Immunization not carried out because of patient decision for reasons of belief or group pressureBillable
- Z28.2Immunization not carried out because of patient decision for other and unspecified reasonHeader
- Z28.20Immunization not carried out because of patient decision for unspecified reasonBillable
- Z28.21Immunization not carried out because of patient refusalBillable
- Z28.29Immunization not carried out because of patient decision for other reasonBillable
- Z28.3Underimmunization statusHeader
- Z28.31Underimmunization for COVID-19 statusHeader
- Z28.310Unvaccinated for COVID-19Billable
- Z28.311Partially vaccinated for COVID-19Billable
- Z28.39Other underimmunization statusBillable
- Z28.8Immunization not carried out for other reasonHeader
- Z28.81Immunization not carried out due to patient having had the diseaseBillable
- Z28.82Immunization not carried out because of caregiver refusalBillable
- Z28.83Immunization not carried out due to unavailability of vaccineBillable
- Z28.89Immunization not carried out for other reasonBillable
- Z28.9Immunization not carried out for unspecified reasonBillable
Code also
The CDC tabular list says a second code may be needed with this one. The note does not set which is listed first.
From Z28. A note on a category applies to every code under it.
Code also, if applicable, encounter for immunization safety counseling (Z71.85)
Use additional code
The CDC tabular list says to add the code named here after this one when it applies.
From Z28.3. A note on a category applies to every code under it.
Use additional code, if applicable, to identify:
- Z28.0-Immunization not carried out because of contraindication
- Z28.2-Immunization not carried out because of patient decision for other and unspecified reason
- Z28.1Immunization not carried out because of patient decision for reasons of belief or group pressure
- Z28.8-Immunization not carried out for other reason
Related conditions
Related pages
- Z28.310 code detailsNotes, nearby codes, CMS-HCC group
- Category Z28Every code under it
- Chapter 21Factors influencing health status
- ICD-10 codes by conditionA to Z
- Check a list of ICD-10 codes
- Denial code CO-11Diagnosis does not support the procedure
- Denial code CO-146Diagnosis invalid for the date of service
- HCPCS Level II code lookup
Questions
What is the ICD-10 code for Unimmunized for COVID-19?
The ICD-10-CM index points "Unimmunized for COVID-19" to Z28.310, Unvaccinated for COVID-19. Z28.310 is a billable code.
Is Z28.310 billable?
Yes. Z28.310 is a billable code in the FY2027 ICD-10-CM file. Use a more specific code when the record documents one.
What documentation notes apply to Z28.310?
The CDC tabular list gives 5 "use additional code" notes for Z28.310 and the categories above it. They are listed on this page.
What chapter is Z28.310 in?
Chapter 21. Factors influencing health status.
When do ICD-10-CM codes change?
Every October 1, with the new fiscal year file. Some years add April 1 updates. This page uses the FY2027 file, effective October 1, 2026.