2026 ICD-10-CM Diagnosis Code Z58.6Inadequate drinking-water supply

ICD-10-CM Codes›Z00–Z99›Z55-Z65›Z58

ICD-10-CM Z58.6
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

Z58.6 is a billable ICD-10-CM diagnosis code for inadequate drinking-water supply. 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 able to access potable water with difficulty. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Socioeconomic/psychosocial factors.

Code Identity

ICD-10-CM Code
Z58.6
Billable Status
Yes — Valid for Submission
Code Describes
Inadequate drinking-water supply
Short Description
Inadequate drinking-water supply
Same as the full description in the CMS dataset.
Parent Code
Z58
Problems related to physical environment

Code Classification

ChapterZ00–Z99Factors influencing health status and contact with health services
SectionZ55-Z65Persons with potential health hazards related to socioeconomic and psychosocial circumstances
CategoryZ58Problems related to physical environment
This CodeZ58.6Inadequate drinking-water supply

Code EditsBilling

Medicare Code Editor checks that affect claim validity for Z58.6.

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

Z58.6 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.

  • Able to access potable water with difficulty
  • Inadequate drinking water supply
  • Inadequate sanitation
  • Water supply insufficient

Tabular List NotesGuidance

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

Inclusion Terms

  • Lack of safe drinking water

Type 2 Excludes

  • deprivation of water T73.1

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.

    • Inadequate, inadequacy
      • drinking-water supply
    • Lack of
      • safe drinking water
    • Lack of
      • water
        • safe drinking
    • Water
      • lack of
        • safe drinking

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 Z58.6 replaces the following previously assigned code(s):

  • Z59.4 - Lack of adequate food
  • Z59.4 - Lack of adequate food and safe drinking water
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 Z58.6Overview

Is Z58.6 (Problems related to physical environment) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report inadequate drinking-water supply on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

Can Z58.6 be a principal diagnosis?

No. The Medicare Code Editor rejects this code as a principal diagnosis because inadequate drinking-water supply describes a circumstance that influences health status rather than a current illness. Report it as a secondary diagnosis.

Is Z58.6 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 inadequate drinking-water supply on inpatient claims.