2026 ICD-10-CM Diagnosis Code Z55.0Illiteracy and low-level literacy

ICD-10-CM Codes›Z00–Z99›Z55-Z65›Z55

ICD-10-CM Z55.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z55.0 is a billable ICD-10-CM diagnosis code for illiteracy and low-level literacy. 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 educational problem. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Socioeconomic/psychosocial factors.

Code Identity

ICD-10-CM Code
Z55.0
Billable Status
Yes — Valid for Submission
Code Describes
Illiteracy and low-level literacy
Short Description
Illiteracy and low-level literacy
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 CodeZ55.0Illiteracy and low-level literacy

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z55.0.

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

Z55.0 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.

  • Educational problem
  • Finding related to ability to read
  • Finding related to literacy level
  • Illiteracy
  • Illiterate literacy level
  • Literacy problems
  • Low-level literacy
  • Unable to read

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.

    • Illiteracy
    • Low
      • level of literacy
    • Problem(with) (related to)
      • illiteracy
    • Problem(with) (related to)
      • literacy
        • low level

Clinical ClassificationClinical

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

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

Convert Z55.0 to ICD-9-CMHistory

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

ICD-9-CM
V62.3 Educational circumstance
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 Z55.0Overview

Is Z55.0 (Problems related to education and literacy) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report illiteracy and low-level literacy on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z55.0 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because illiteracy and low-level literacy describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z55.0 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 illiteracy and low-level literacy on inpatient claims.

What is the ICD-9 equivalent of Z55.0?

Under the General Equivalence Mappings, illiteracy and low-level literacy converts to ICD-9-CM V62.3 (educational circumstance). The mapping is approximate, so confirm the match fits the documentation.