ICD-10-CM 2027
ICD-10 code for Delinquent immunization status
From the official ICD-10-CM alphabetic index entry “Delinquent immunization status”. Page updated September 29, 2026.
About coding Delinquent immunization status
The ICD-10-CM code for Delinquent immunization status is Z28.39 (Other underimmunization status). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on Z28.39.
Within Z28.3, choose Z28.39 (Other underimmunization status) only when documentation doesn't support a more specific option: underimmunization for COVID-19 status (Z28.31).
It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.
In MS-DRG v44.0, it is part of the grouping logic for DRG 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.
More specific Delinquent immunization status codes (official index)
- COVID-19 Z28.31 — Underimmunization for COVID-19 status
Common questions about Delinquent immunization status ICD-10 codes
What is the ICD-10 code for Delinquent immunization status?
- Z28.39 — Other underimmunization status. More specific codes apply when the documentation supports them: Z28.31.
What is the ICD-10 code for covid-19 delinquent immunization status?
- Z28.31 — Underimmunization for COVID-19 status (header code; choose a more specific subcode).
Is Z28.39 billable?
- Yes. Z28.39 is a billable/specific ICD-10-CM code valid for FY2027 (October 1, 2026 – September 30, 2027).
Can Z28.39 be used as a principal diagnosis?
- No. It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.
Is Z28.39 a CC or MCC?
- No. Z28.39 is neither a CC nor an MCC under MS-DRG v44.0.