Z03.818 – Encounter for observation for suspected exposure to other biological agents ruled out

ICD-10-CM 2027 diagnosis code · Persons encountering health services for examinations

Billable code

ICD-10-CM code Z03.818

Code: Z03.818 (claims format: Z03818)
Description: Encounter for observation for suspected exposure to other biological agents ruled out
Short description: Encntr for obs for susp expsr to oth biolg agents ruled out
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: Z00-Z13 Persons encountering health services for examinations
Parent codes: Z03 › Z03.8 › Z03.81

Notes inherited from parent codes

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

Z03 – Encounter for medical observation for suspected diseases and conditions ruled out

Applicable to:

This category is to be used when a person without a diagnosis is suspected of having an abnormal condition, without signs or symptoms, which requires study, but after examination and observation, is ruled out. This category is also for use for administrative and legal observation status.

Excludes1 (not coded here):

contact with and (suspected) exposures hazardous to health (Z77.-)
encounter for observation and evaluation of newborn for suspected diseases and conditions ruled out (Z05.-)
person with feared complaint in whom no diagnosis is made (Z71.1)
signs or symptoms under study- code to signs or symptoms

Block Z00-Z13

Excludes2 (not included here):

examinations related to pregnancy and reproduction (Z30-Z36, Z39.-)

Notes:

Nonspecific abnormal findings disclosed at the time of these examinations are classified to categories R70-R94.

Index terms for Z03.818

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

Related codes in Z03.81

Z03.810 – Encounter for observation for suspected exposure to anthrax ruled outBillable

Frequently asked questions

What is ICD-10 code Z03.818?

Z03.818 is the ICD-10-CM code for encounter for observation for suspected exposure to other biological agents ruled out, in the block Z00-Z13 (Persons encountering health services for examinations).

Is Z03.818 a billable code?

Yes. Z03.818 is a billable/specific code that can be used to indicate a diagnosis for reimbursement purposes.

What category does Z03.818 belong to?

It belongs to category Z03 – Encounter for medical observation for suspected diseases and conditions ruled out.

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.