2026 ICD-10-CM Diagnosis Code Z03.821Encounter for observation for suspected ingested foreign body ruled out

ICD-10-CM Codes›Z00–Z99›Z00-Z13›Z03

ICD-10-CM Z03.821
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z03.821 is a billable ICD-10-CM diagnosis code for encounter for observation for suspected ingested foreign body ruled out. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is not accepted as a principal diagnosis by the Medicare Code Editor and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Encounter for observation and examination for conditions ruled out (excludes infectious disease, neoplasm, mental disorders).

Code Identity

ICD-10-CM Code
Z03.821
Billable Status
Yes — Valid for Submission
Code Describes
Encounter for observation for suspected ingested foreign body ruled out
Short Description
Enctr for observation for suspected ingested fb ruled out
Parent Code
Z03.82
Encounter for observation for suspected foreign body ruled out

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ00-Z13Persons encountering health services for examinations
CategoryZ03Encounter for medical observation for suspected diseases and conditions ruled out
This CodeZ03.821Encounter for observation for suspected ingested foreign body ruled out

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z03.821.

Unacceptable principal diagnosis
There are selected codes that describe a circumstance which influences an individual's health status but not a current illness or injury, or codes that are not specific manifestations but may be due to an underlying cause. These codes are considered unacceptable as a principal diagnosis.

Present on Admission (POA)Billing

Z03.821 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Observation(following) (for) (without need for further medical care)
      • suspected, ruled out
        • foreign body
          • ingested

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR FAC003
Encounter for observation and examination for conditions ruled out (excludes infectious disease, neoplasm, mental disorders)
Default principal diagnosis: inpatient No · outpatient Yes

Code History & ChangesHistory

Replacement Z03.821 replaces the following previously assigned code(s):

  • Z03.89 - Encntr for obs for oth suspected diseases and cond ruled out
FY 2021AddedAdded to the ICD-10-CM code setEffective October 1, 2020.
FY 2022–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z03.821Overview

Is Z03.821 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report encounter for observation for suspected ingested foreign body ruled out on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z03.821 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because encounter for observation for suspected ingested foreign body ruled out describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z03.821 exempt from POA reporting?

Yes. CMS lists this code among those exempt from present on admission reporting, so hospitals do not assign a POA indicator for encounter for observation for suspected ingested foreign body ruled out on inpatient claims.