Z58.6Inadequate drinking-water supply

Z58.6 is the ICD-10-CM diagnosis code for inadequate drinking-water supply. It belongs to category Z58 (problems related to physical environment), block Z55-Z65 (persons with potential health hazards related to socioeconomic and psychosocial circumstances) and chapter 21 (factors influencing health status and contact with health services). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within Z58 (problems related to physical environment), Z58.6 is specifically for inadequate drinking-water supply. Related codes cover other problems related to physical environment (Z58.8).

The conditions in its Excludes2 note aren't part of Z58.6, but may be coded alongside it if the patient has both: deprivation of water (T73.1).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 951 (Other Factors Influencing Health Status, relative weight 0.5577), in MDC 23 (Factors Influencing Health Status and Other Contacts with Health Services), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It is not acceptable as the principal diagnosis for an inpatient stay; it may be reported as a secondary diagnosis.

It is exempt from present-on-admission (POA) reporting, so no POA indicator is required.

It was added in FY2022, effective October 1, 2021.