Z28.39 – Other underimmunization status

ICD-10-CM 2027 diagnosis code · Persons with potential health hazards related to communicable diseases

Billable code

ICD-10-CM code Z28.39
Code
Z28.39 (claims format: Z2839)
Description
Other underimmunization status
Billable
Yes – valid for HIPAA-covered transactions
Valid for
Dates of service October 1, 2026 – September 30, 2027 (FY2027)
Chapter
21. Factors influencing health status and contact with health services (Z00-Z99)
Block
Z20-Z29 Persons with potential health hazards related to communicable diseases
Parent codes
Z28 › Z28.3

Notes for Z28.39

Applicable to:
  • Delinquent immunization status
  • Lapsed immunization schedule status

Notes inherited from parent codes

Instructional notes at a category or block level apply to every code below it.

Z28 – Immunization not carried out and underimmunization status

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

Z28.3 – Underimmunization status

Use additional code:
  • code, if applicable, to identify:
  • immunization not carried out because of contraindication (Z28.0-)
  • immunization not carried out because of patient decision for other and unspecified reason (Z28.2-)
  • immunization not carried out because of patient decision for reasons of belief or group pressure (Z28.1)
  • immunization not carried out for other reason (Z28.8-)

Index terms for Z28.39

Entries in the ICD-10-CM alphabetic index that lead to this code:

Related codes in Z28.3

Frequently asked questions

What is ICD-10 code Z28.39?

Z28.39 is the ICD-10-CM code for other underimmunization status, in the block Z20-Z29 (Persons with potential health hazards related to communicable diseases).

Is Z28.39 a billable code?

Yes. Z28.39 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does Z28.39 belong to?

It belongs to category Z28 – Immunization not carried out and underimmunization status.

Source: CDC/NCHS ICD-10-CM FY2027 code files, tabular list and index. Reference only – code assignment must follow the official ICD-10-CM guidelines and documentation in the medical record.