Factors influencing health status and contact with health services (Z00–Z99) ICD-10-CM
Chapter 21 of the ICD-10-CM classification spans codes Z00–Z99 and contains 1,800 diagnosis codes for factors influencing health status and contact with health services, of which 1,373 are billable. The chapter is organized into 15 sections listed below, each linking to its code ranges and individual codes.
Chapter Coding Notes
Note: 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.
Sections in This Chapter 15 ranges · 1,800 codes
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
About Chapter 21
ICD-10 Chapter 21 codes Z00–Z99 are used for documenting factors that affect a patient's health status and reasons for contact with health services outside of active disease or injury. These codes help capture encounters like routine checkups, screenings, and ongoing care management.
This chapter includes codes for situations such as general health examinations, vaccination encounters, and monitoring a patient’s health after treatment or surgery. It also covers codes for addressing personal or family history of diseases, lifestyle factors, or socioeconomic circumstances impacting health. For healthcare providers and coders, these codes are essential for accurately representing status factors that influence care without describing a current illness. They ensure a comprehensive record of preventive care, follow-ups, and other interactions focused on maintaining health rather than treating active medical conditions.
Questions About This Page
How many codes are in the Z00-Z99 range?
The Z00-Z99 range contains 1,800 ICD-10-CM diagnosis codes in FY 2026. 1,373 of them are billable, and the rest are category headers that organize the chapter.
What conditions does Z00-Z99 cover?
The range covers factors influencing health status and contact with health services. The sections listed above break it into groups of related conditions, and each one links to its own page with the full code list.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
