2027 ICD-10-CM Diagnosis Code E86.0Dehydration

ICD-10-CM Codes›E00–E89›E70-E88›E86

ICD-10-CM E86.0
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

E86.0 is a billable ICD-10-CM diagnosis code for dehydration. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) and groups to MS-DRG 640 through 641, 791, 793. 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to E86.0: its own notes plus those printed at E86, block E70-E88, and Chapter 4. A note printed at a category, block or chapter applies to every code under it.

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From E86 Volume depletion applies to 3 codes
  • dehydration of newborn (P74.1)
  • postprocedural hypovolemic shock (T81.19)
  • traumatic hypovolemic shock (T79.4)
From Block E70-E88 Metabolic disorders applies to 286 codes
  • androgen insensitivity syndrome (E34.5-)
  • congenital adrenal hyperplasia (E25.0)
  • hemolytic anemias attributable to enzyme disorders (D55.-)
  • Marfan syndrome (Q87.4-)
  • 5-alpha-reductase deficiency (E29.1)
From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • transitory endocrine and metabolic disorders specific to newborn (P70-P74)

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.

From E86 Volume depletion applies to 3 codes
  • hypovolemic shock NOS (R57.1)
From Block E70-E88 Metabolic disorders applies to 286 codes
  • Ehlers-Danlos syndromes (Q79.6-)

Use Additional Code

Add a second code, after this one, to fully describe the condition.

From E86 Volume depletion applies to 3 codes
  • code(s) for any associated disorders of electrolyte and acid-base balance (E87.-)

Notes

General instructions on how these codes are used.

From Chapter 4 (E00-E89) Endocrine, nutritional and metabolic diseases applies to 973 codes
  • All neoplasms, whether functionally active or not, are classified in Chapter 2. Appropriate codes in this chapter (i.e. E05.8, E07.0, E16-E31, E34.-) may be used as additional codes to indicate either functional activity by neoplasms and ectopic endocrine tissue or hyperfunction and hypofunction of endocrine glands associated with neoplasms and other conditions classified elsewhere.

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name E86.0, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming E86.0: they are not reported together with it, unless the two conditions are unrelated.

  • R68.2 Dry mouth, unspecified
    dry mouth due to dehydration (E86.0)

Excludes2 3

These codes carry an Excludes2 note naming E86.0: its condition is not part of those codes, and both may be reported when the patient has both.

  • E63 Other nutritional deficiencies
    dehydration (E86.0)
  • R79.1 Abnormal coagulation profile
    abnormality of fluid, electrolyte or acid-base balance (E86-E87) names E86-E87, which includes this code
  • Block T80-T88 Complications of surgical and medical care, not elsewhere classified
    disorders of fluid and electrolyte imbalance (E86-E87) names E86-E87, which includes this code

Code Also 1

These codes say E86.0 may also be needed to fully describe the condition. The note gives no sequencing direction.

  • R11.16 Cannabis hyperemesis syndrome
    dehydration (E86.0)

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 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.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About E86.0Overview

What is the ICD-10 code for dehydration?

The ICD-10-CM code for dehydration is E86.0 (sometimes written as E860). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does E86.0 group to?

When dehydration is the principal diagnosis on an inpatient stay, it groups to MS-DRG 793, 791, 641, 640, with relative weights from 0.7864 to 4.2192 depending on complications. Higher weights mean higher Medicare reimbursement.

Can E86.0 be reported with P74.1?

Not as a rule. The Excludes1 note at E86, which applies to E86.0, lists "dehydration of newborn (P74.1)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

Does E86.0 need an additional code?

When the condition applies, yes. The Use Additional Code note at E86, which applies to E86.0, reads: code(s) for any associated disorders of electrolyte and acid-base balance (E87.-). The additional code is reported after E86.0.