Encounter for immunization (Z23) ICD-10-CM
The Z23 code range covers encounter for immunization with 1 ICD-10-CM diagnosis codes. 1 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Code First
Certain conditions have both an underlying etiology and multiple body system manifestations due to the underlying etiology. For such conditions, the ICD-10-CM has a coding convention that requires the underlying condition be sequenced first followed by the manifestation. Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code. These instructional notes indicate the proper sequencing order of the codes, etiology followed by manifestation.
- any routine childhood examination
Code Also
A "code also" note instructs that two codes may be required to fully describe a condition, but this note does not provide sequencing direction.
- , if applicable, encounter for immunization safety counseling Z71.85
- procedure codes are required to identify the types of immunizations given
Codes in the Z23 Range 1 codes · 1 billable
- Z23 Encounter for immunization
About the Z23 Code Range
The ICD-10 code Z23 is used specifically for documenting encounters where a patient receives immunizations or vaccinations. This code covers all types of immunizations given to prevent infectious diseases.
Z23 applies when patients are vaccinated against various conditions such as measles, mumps, rubella, influenza, human papillomavirus (HPV), pneumococcal infections, tetanus, diphtheria, pertussis, varicella (chickenpox), and hepatitis A and B. Common synonyms like "herpes zoster vaccination given," "influenza vaccination status," or "travel vaccination given" represent specific examples of immunization encounters covered under this code. This helps medical coders accurately identify immunization services provided without documenting a current illness. Understanding ICD-10 code for encounter for immunization Z23 assists both healthcare providers and coders in correctly classifying visits solely for preventive vaccination, supporting clear communication in health records and insurance claims.
Questions About This Page
How many billable codes are in the Z23 range?
Of the 1 codes in this range, 1 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the Z23 range classify?
The range classifies encounter for immunization. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
