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Z28.39

Z28.39Other underimmunization status

Billable / specific codeICD-10-CMPOA exempt

Z28.39 is a billable, specific ICD-10-CM code for other underimmunization status. It is valid for submission on a claim.

Inclusion terms

Alternative wordings a physician may use in the chart for this same code.

  • Delinquent immunization status
  • Lapsed immunization schedule status

Risk adjustment

Z28.39 does not map to an HCC and does not risk-adjust under CMS-HCC V28. That is normal — most ICD-10 codes do not. It still needs to be coded correctly; it just will not move a RAF score.

How Z28.39 is indexed

Coders do not find codes by browsing the tabular list — they look them up in the alphabetic index, under the word the physician wrote. These are the index entries that lead here, so you can see which chart wordings map to Z28.39.

  • Delinquent immunization status
  • Lapsed immunization schedule status
  • Underimmunization status
  • Statusdelinquent immunization
  • Statuslapsed immunization schedule
  • Statusunderimmunization

Related codes at this level

Codes that share Z28.3. If Z28.39 is not quite right, the correct code is usually one of these.

Questions about Z28.39

Is Z28.39 a billable ICD-10-CM code?
Yes. Z28.39 is a billable, specific ICD-10-CM code and is valid for submission on a claim.
Where does Z28.39 sit in the tabular list?
Factors influencing health status and contact with health services (Z00-Z99), in the block Persons with potential health hazards related to communicable diseases (Z20-Z29).
ICD-10-CMFY2026-Apr· effective April 1, 2026

Loaded directly from the CMS/NCHS ICD-10-CM public-domain release — see data sources and our editorial policy. If this page disagrees with the CMS tabular list, this page is wrong. Reference information for professional coders; not medical or billing advice.