Z03.818 Encounter for observation for suspected exposure to other biological agents ruled out
The ICD-10-CM code for Encounter for observation for suspected exposure to other biological agents ruled out is Z03.818 (FY2026). It is a billable, claim-ready diagnosis code.
Classification
- Section
- Z00-Z13: Persons encountering health services for examinations (Z00-Z13)
- Category Z03
- 19 codes (14 billable)
- FY2026 Status
- Stable since FY2024
Also Known As
ICD-10-CM Alphabetic Index entries that lead to Z03.818:
- Encounter (with health service) (for) › suspected exposure (to), ruled out › biological agents NEC
- Encounter (with health service) (for) › observation (for) (ruled out) › exposure to (suspected) › biological agent NEC
- Observation (following) (for) (without need for further medical care) › suspected, ruled out › exposure (to) › biological agent NEC
U.S. Hospital Utilization
- An estimated 4,335 U.S. inpatient stays in 2023 included Z03.818 among the documented diagnoses.
Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.
Official Coding Guidelines
Used with any code in range A00.0-T88.9, Z00-Z991) Used with any code in the range of A00.0-T88.9, Z00-Z99 An external cause code may be used with any code in the range of A00.0-T88.9, Z00-Z99, classification that represents a health condition due to an external cause. Though they are most applicable to injuries, they are also valid for use with such things as infections or diseases due to an external source, and other health conditions, such as a heart attack that occurs during strenuous physical activity.
Additional codes with observation code (fragment)observation code, but only if they are unrelated to the suspected condition being observed.
Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026