Coding and coverage · ICD-10-CM

Z28

Z28.2 Immunization not carried out because of patient decision for other and unspecified reason

Not billable (header)Chapter 21

Report one of the more specific codes below.

Codes under this one

  • Z28.20 Immunization not carried out because of patient decision for unspecified reason
  • Z28.21 Immunization not carried out because of patient refusal
  • Z28.29 Immunization not carried out because of patient decision for other reason

Instructional notes

Chapter 21

Notes
  • Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
  • (a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
  • (b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.

Z28

Code also
  • , if applicable, encounter for immunization safety counseling (Z71.85)
Includes
  • vaccination not carried out

Chapter 21: Factors influencing health status and contact with health services · Z20-Z29 Persons with potential health hazards related to communicable diseases (Z20-Z29)

Source: ICD-10-CM FY 2027 code descriptions and tabular list (CMS and CDC National Center for Health Statistics), effective 2026-10-01 through 2027-09-30 · CMS ICD-10 files. HCC mapping: CMS-HCC V28, payment year 2027. As of 2026-11-04.

Coverage and payment depend on the claim details; confirm with the Medicare Administrative Contractor.