2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

Z58.6 is a billable ICD-10-CM diagnosis code for inadequate drinking-water supply. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 951. 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 the other POA exempt codes in Persons with potential health hazards related to socioeconomic and psychosocial circumstances (Z55-Z65).

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Able to access potable water with difficulty
  • Inadequate drinking water supply
  • Lack of potable water in residence
  • Water supply insufficient

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to Z58.6: its own notes plus those printed at Z58 and Chapter 21. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Lack of safe drinking water

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

On Z58.6 itself
  • deprivation of water (T73.1)
From Z58 Problems related to physical environment applies to 3 codes
  • occupational exposure (Z57.-)

Notes

General instructions on how these codes are used.

From Chapter 21 (Z00-Z99) Factors influencing health status and contact with health services applies to 1,425 codes
  • Z codes represent reasons for encounters. A corresponding procedure code must accompany a Z code if a procedure is performed. Categories Z00-Z99 are provided for occasions when circumstances other than a disease, injury or external cause classifiable to categories A00-Y89 are recorded as 'diagnoses' or 'problems'. This can arise in two main ways:
  • (a) When a person who may or may not be sick encounters the health services for some specific purpose, such as to receive limited care or service for a current condition, to donate an organ or tissue, to receive prophylactic vaccination (immunization), or to discuss a problem which is in itself not a disease or injury.
  • (b) When some circumstance or problem is present which influences the person's health status but is not in itself a current illness or injury.

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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 2023–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About Z58.6Overview

What is the ICD-10 code for inadequate drinking-water supply?

The ICD-10-CM code for inadequate drinking-water supply is Z58.6 (sometimes written as Z586). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does Z58.6 group to?

On inpatient claims, inadequate drinking-water supply maps to MS-DRG 951 (other Factors Influencing Health Status), which carries a relative weight of 0.5574. Higher weights mean higher Medicare reimbursement.

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. The code appears in the Persons with potential health hazards related to socioeconomic and psychosocial circumstances (Z55-Z65) range of the CMS exempt list.