2026 ICD-10-CM Diagnosis Code Z55.5Less than a high school diploma

ICD-10-CM Codes›Z00–Z99›Z55-Z65›Z55

ICD-10-CM Z55.5
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z55.5 is a billable ICD-10-CM diagnosis code for less than a high school diploma. 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. Coders also document this condition as academic underachievement. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Socioeconomic/psychosocial factors.

Code Identity

ICD-10-CM Code
Z55.5
Billable Status
Yes — Valid for Submission
Code Describes
Less than a high school diploma
Short Description
Less than a high school diploma
Same as the full description in the CMS dataset.
Parent Code
Z55
Problems related to education and literacy

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ55-Z65Persons with potential health hazards related to socioeconomic and psychosocial circumstances
CategoryZ55Problems related to education and literacy
This CodeZ55.5Less than a high school diploma

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z55.5.

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

Z55.5 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.

  • Academic underachievement
  • Less than a high school diploma
  • School maladjustment

Tabular List NotesGuidance

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

Inclusion Terms

  • No general equivalence degree (GED)

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.

    • Educational handicap
      • less than a high school diploma
    • Educational handicap
      • no general equivalence degree (GED)
    • Less than a high school diploma
    • No
      • general equivalence degree (GED)

Clinical ClassificationClinical

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

CCSR FAC019
Socioeconomic/psychosocial factors
Default principal diagnosis: inpatient No · outpatient No

Code History & ChangesHistory

Replacement Z55.5 replaces the following previously assigned code(s):

  • Z55.8 - Other problems related to education and literacy
FY 2022AddedAdded to the ICD-10-CM code setEffective October 1, 2021.
FY 2023–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About Z55.5Overview

Is Z55.5 (Problems related to education and literacy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report less than a high school diploma on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z55.5 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because less than a high school diploma describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z55.5 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 less than a high school diploma on inpatient claims.