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 1,817 diagnosis codes for factors influencing health status and contact with health services, of which 1,387 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 · 1,817 codes
The info icon previews the code ranges inside each row and its instructional notations from the official Tabular List.
About Chapter 21
These entries describe reasons for contact with health services and circumstances that can affect health status. They include encounters for examinations, care related to reproduction, other specific care, and other circumstances.
Other blocks identify genetic carrier status or susceptibility to disease, resistance to antimicrobial drugs, hormone and other factor receptor status, retained fragments of foreign material, and hormone sensitivity of cancer. Separate blocks cover do not resuscitate status, blood type, and body mass index.
Blocks for potential health hazards distinguish communicable diseases; social, economic, and psychological circumstances; and family or personal history and other conditions affecting health status.
FY 2027 changes: The FY 2027 ICD-10-CM update, effective October 1, 2026, added 16 codes, revised 1 code title and deleted 7 codes in this chapter.
Questions About This Page
How many codes are in the Z00-Z99 range?
The Z00-Z99 range contains 1,817 ICD-10-CM diagnosis codes in FY 2027. 1,387 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 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
