ICD-10-CM · Chapter 21 · Z00–Z99
Z28.3
Underimmunization status
Factors influencing health status and contact with health services
Heads up:this is a parent code. It's typically not directly billable — you need to drill down to a more specific child code (one with additional digits) to use on a claim.
Quick facts
- Code
- Z28.3
- Type
- Category / header (non-billable)
- ICD-10-CM chapter
- Chapter 21 — Factors influencing health status and contact with health services
- Category
- Z28 — Immunization not carried out and underimmunization status
- Specificity
- 4 characters
How coders use this code
ICD-10-CM Z28.3 is a category (header) for underimmunization status. It is generally not reported directly on a claim — coders drill down to a more specific child code (one with additional characters) that matches the documentation. Use the related codes below to find the billable code that fits, and verify against the annual NCHS/CMS guidelines.
Related codes in Z28
- Z28Immunization not carried out and underimmunization status
- Z28.0Immunization not carried out because of contraindication
- Z28.01Immunization not carried out because of acute illness of patient
- Z28.02Immunization not carried out because of chronic illness or condition of patient
- Z28.03Immunization not carried out because of immune compromised state of patient
- Z28.04Immunization not carried out because of patient allergy to vaccine or component
- Z28.09Immunization not carried out because of other contraindication
- Z28.1Immunization not carried out because of patient decision for reasons of belief or group pressure
- Z28.2Immunization not carried out because of patient decision for other and unspecified reason
- Z28.20Immunization not carried out because of patient decision for unspecified reason
- Z28.21Immunization not carried out because of patient refusal
- Z28.29Immunization not carried out because of patient decision for other reason
- Z28.31Underimmunization for COVID-19 status
- Z28.310Unvaccinated for COVID-19
- Z28.311Partially vaccinated for COVID-19
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