2026 ICD-10-CM Diagnosis Code Z00.121Encounter for routine child health examination with abnormal findings

ICD-10-CM Codes›Z00–Z99›Z00-Z13›Z00

ICD-10-CM Z00.121
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z00.121 is a billable ICD-10-CM diagnosis code for encounter for routine child health examination with abnormal findings. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). The code is restricted by the Medicare Code Editor to pediatric patients (age 0 through 17), not accepted as a principal diagnosis, and exempt from POA reporting. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Medical examination/evaluation.

This medical diagnosis code is frequently used in Pediatrics medical specialties to designate conditions such routine child health examination.

Code Identity

ICD-10-CM Code
Z00.121
Billable Status
Yes — Valid for Submission
Code Describes
Encounter for routine child health examination with abnormal findings
Short Description
Encounter for routine child health exam w abnormal findings
Parent Code
Z00.12
Encounter for routine child health examination

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ00-Z13Persons encountering health services for examinations
CategoryZ00Encounter for general examination without complaint, suspected or reported diagnosis
This CodeZ00.121Encounter for routine child health examination with abnormal findings

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z00.121.

Pediatric diagnoses
The Medicare Code Editor detects inconsistencies in pediatric cases by checking a patient's age and any diagnosis on the patient's record. The pediatric code edits apply to patients age range is 0–17 years inclusive (e.g., Reye's syndrome, routine child health exam).
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

Z00.121 is exempt from POA reporting on inpatient claims to general acute care hospitals. Review other POA exempt codes.

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • 1 year examination abnormal - for observation
  • 1 year examination abnormal - on treatment
  • 1 year examination abnormal - referred
  • 10 day examination abnormal - for observation
  • 10 day examination abnormal - on treatment
  • 10 year examination abnormal - for observation
  • 10 year examination abnormal - on treatment
  • 10 year examination abnormal - referred
  • 15 year examination abnormal - for observation
  • 15 year examination abnormal - on treatment
  • 15 year examination abnormal - referred
  • 18 month examination abnormal - for observation
  • 18 month examination abnormal - on treatment
  • 18 month examination abnormal - referred
  • 2.5 year examination abnormal - for observation
  • 2.5 year examination abnormal - on treatment
  • 2.5 year examination abnormal - referred
  • 3.5 year examination abnormal - for observation
  • 3.5 year examination abnormal - on treatment
  • 3.5 year examination abnormal - referred
  • 4.5 year examination abnormal - for observation
  • 4.5 year examination abnormal - on treatment
  • 4.5 year examination abnormal - referred
  • 6 week examination abnormal - for observation
  • 6 week examination abnormal - on treatment
  • 6 week examination abnormal - referred
  • 8 month examination abnormal - for observation
  • 8 month examination abnormal - on treatment
  • 8 month examination abnormal - referred
  • 8 week examination abnormal - for observation
  • 8 week examination abnormal - on treatment
  • 8 week examination abnormal - referred
  • 8-9 month examination abnormal - for observation
  • 8-9 month examination abnormal - on treatment
  • 8-9 month examination abnormal - referred
  • Abnormal wellness exam
  • Child 21 month examination abnormal - for observation
  • Child 21 month examination abnormal - on treatment
  • Child 21 month examination abnormal: refer
  • Child 3 year exam abnormal - for observation
  • Child 3 year exam abnormal - on treatment
  • Child 3 year exam abnormal - referred
  • Child 39 month examination abnormal - for observation
  • Child 39 month examination abnormal - on treatment
  • Child 39 month examination abnormal - referred
  • Child 6 month examination abnormal - for observation
  • Child 6 month examination abnormal - on treatment
  • Child 6 month examination abnormal - referred
  • Child 7 month examination abnormal - on treatment
  • Child 7 month examination abnormal - referred
  • Seen by pediatric neurologist
  • Seen by pediatric oncologist
  • Seen by pediatrician

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Use Additional Code

  • code to identify abnormal findings

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.

    • Admission(for)
      • examination at health care facility (adult)
        • hearing
          • infant or child (over 28 days old)
            • with abnormal findings
    • Admission(for)
      • examination at health care facility (adult)
        • vision
          • infant or child (over 28 days old)
            • with abnormal findings
    • Admission(for)
      • vision examination
        • infant or child (over 28 days old)
          • with abnormal findings
    • Examination(for) (following) (general) (of) (routine)
      • child (over 28 days old)
        • with abnormal findings
    • Examination(for) (following) (general) (of) (routine)
      • hearing
        • infant or child (over 28 days old)
          • with abnormal findings
    • Examination(for) (following) (general) (of) (routine)
      • vision
        • infant or child (over 28 days old)
          • with abnormal findings
    • Hearing examination
      • infant or child (over 28 days old)
        • with abnormal findings
    • Immunization
      • appropriate for age
        • child (over 28 days old)
          • with abnormal findings
    • Screening(for)
      • infant or child (over 28 days old)
        • with abnormal findings
    • Test, tests, testing(for)
      • hearing
        • infant or child (over 28 days old)
          • with abnormal findings
    • Test, tests, testing(for)
      • vision
        • infant or child (over 28 days old)
          • with abnormal findings

Clinical ClassificationClinical

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

CCSR FAC014
Medical examination/evaluation
Default principal diagnosis: inpatient No · outpatient Yes

Patient EducationClinical

Health Checkup

Regular checkups with your health care provider are different from appointments for sickness or injury. These checkups include physical exams as well as preventive care. Preventative care may include:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert Z00.121 to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
V20.2 Routin child health exam
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z00.121Overview

Is Z00.121 (Encounter for routine child health examination) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report encounter for routine child health examination with abnormal findings on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z00.121 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because encounter for routine child health examination with abnormal findings describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Who can Z00.121 be reported for?

The Medicare Code Editor checks encounter for routine child health examination with abnormal findings against patient demographics: this code is intended for pediatric patients (age 0 through 17). Claims outside these limits are flagged as inconsistent.

Is Z00.121 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 routine child health examination with abnormal findings on inpatient claims.

What is the ICD-9 equivalent of Z00.121?

Under the General Equivalence Mappings, encounter for routine child health examination with abnormal findings converts to ICD-9-CM V20.2 (routin child health exam). The mapping is approximate, so confirm the match fits the documentation.