Is ICD-10-CM code Z04 billable?

No, Z04 (Encounter for examination and observation for other reasons) is a non-billable ICD-10-CM code. It must be coded to a more specific subcategory before it can be used for reimbursement.

What chapter does ICD-10-CM code Z04 belong to?

Z04 belongs to Chapter 21 of the ICD-10-CM tabular list: Z00–Z99 (Factors Influencing Health Status and Contact with Health Services).

Z04Not billable, use a more specific code below

Encounter for examination and observation for other reasons

In Persons encountering health services for examinations (Z00-Z13), chapter 21: Factors Influencing Health Status and Contact with Health Services

12 billable codes under Z04: none are a CC or MCC; none map to an HCC.

Instructional notes

Includes: conditions that are coded here

encounter for examination for medicolegal reasons
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.

Also applies, from Persons encountering health services for examinations (Z00-Z13)

These notes sit on Z00-Z13 and apply to every code under it, including Z04.

Excludes2: not included here, code separately if applicable

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

Official coding guidelines

From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.

Covers when and how to use Z codes (Z00-Z99) for encounters and supplementary information, including contact, status, history, screening, aftercare, exams, and social determinants of health.

Use of Z Codes in Any Healthcare Setting (page 92)
Z Codes Indicate a Reason for an Encounter or Provide Additional Information about a Patient Encounter (page 93)
Categories of Z Codes (page 93)

Read Section I.C.21 (page 92)

All codes under Z04

Z04 can't be used on a claim. Pick a billable code below; grey headings group them.

Z04 MS-DRGs

As the principal diagnosis, the billable codes under Z04 group to MS-DRG 951, 922, or 923 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.

DRG 951 Other Factors Influencing Health Status (9 of 12 codes)
DRG 922 Other Injury, Poisoning and Toxic Effect Diagnoses with MCC (3 of 12 codes)
DRG 923 Other Injury, Poisoning and Toxic Effect Diagnoses without MCC (3 of 12 codes)

Code history

Valid since FY2016, when ICD-10-CM took effect on October 1, 2015. No changes since.