2026 ICD-10-CM Diagnosis Code E86.0Dehydration

ICD-10-CM Codes›E00–E89›E70-E88›E86

ICD-10-CM E86.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

E86.0 is a billable ICD-10-CM diagnosis code for dehydration. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 640 through 641. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Fluid and electrolyte disorders.

Code Identity

ICD-10-CM Code
E86.0
Billable Status
Yes — Valid for Submission
Code Describes
Dehydration
Short Description
Dehydration
Same as the full description in the CMS dataset.
Parent Code
E86
Volume depletion

Code Classification

ChapterE00–E89Endocrine, nutritional and metabolic diseases
SectionE70-E88Metabolic disorders
CategoryE86Volume depletion
This CodeE86.0Dehydration

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Cataract due to dehydration
  • Dehydration
  • Dehydration caused by radiation
  • Dehydration following exertion
  • Deprivation of water
  • Finding of fluid intake
  • Inadequate oral fluid intake for physiological needs
  • Insufficient fluid intake - finding
  • Isonatremic dehydration
  • Mild dehydration
  • Moderate dehydration
  • Post-exercise state
  • Severe dehydration
  • Signs of dehydration
  • Xerostomia
  • Xerostomia due to dehydration

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.

    • Anhydration
    • Anhydremia
    • Cachexia
      • dehydration
    • Dehydration
    • Dry, dryness
      • mouth
        • due to dehydration
    • Luetscher's syndrome(dehydration)
    • Syndrome
      • Luetscher's (dehydration)

Clinical ClassificationClinical

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

CCSR END011
Fluid and electrolyte disorders
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Dehydration

    the condition that results from excessive loss of water from a living organism.

  • Xerostomia

    decreased salivary flow.

Patient EducationClinical

Fluid and Electrolyte Balance

Electrolytes are minerals that have an electric charge when they are dissolved in water or body fluids, including blood. The electric charge can be positive or negative. You have electrolytes in your blood, urine (pee), tissues, and other body fluids.

The full article covers:

  • What are electrolytes?
  • What are the different types of electrolytes in your body?
  • What is an electrolyte imbalance?
  • What are the different types of electrolyte imbalances?
  • How are electrolyte imbalances diagnosed?
  • What are the treatments for electrolyte imbalances?

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert E86.0 to ICD-9-CMHistory

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

ICD-9-CM
276.51 Dehydration
Exact Match The mapping is direct, with no qualifiers.

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 E86.0Overview

Is E86.0 (Volume depletion) a billable code?

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

What MS-DRG does E86.0 group to?

When dehydration is the principal diagnosis on an inpatient stay, it groups to MS-DRG 640, 641, with relative weights from 0.7782 to 1.3356 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of E86.0?

Under the General Equivalence Mappings, dehydration converts to ICD-9-CM 276.51 (dehydration). The mapping is a direct match.

Footnotes

[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.