E86.1

🧬 ICD-10 CM E86.1 — Hypovolemia

Billable Code Confirmed

ICD-10 CM E86.1 is a valid, billable 5-character ICD-10-CM code for FY2026. Characters 1-3 (E86) define the Volume depletion category; character 4-5 (.1) specify Hypovolemia as the distinct clinical entity. No additional characters are required.

Non-Billable Parent Codes — Never Submit These

❌ E00-E89 — Chapter header — Endocrine, nutritional and metabolic diseases (non-billable category) ❌ E70-E88 — Block header — Metabolic disorders (non-billable block) ❌ E86 — 4-character header — Volume depletion (lacks specificity for hypovolemia vs dehydration vs unspecified) Always submit E86.1 (all 5 characters) when hypovolemia with documented plasma volume depletion is clinically established.

Clinical Context: Hypovolemia vs Dehydration Distinction

ICD-10-CM E86.1 captures loss of circulating plasma volume (water + electrolytes), distinct from E86.0 dehydration which primarily reflects water loss. This specificity matters because hypovolemia carries higher risk of hemodynamic compromise and may drive different treatment pathways (e.g., isotonic vs hypotonic fluid selection). ⁶⁷

Code Classification

ICD-10-CM Diagnosis Code — wRVU, assistant payable, and global period fields are not applicable for diagnosis codes. See CPT Procedural Crosswalk and ICD-10-PCS Crosswalk sections for associated procedure coding guidance.

🔍 Code Description

ICD-10-CM E86.1 classifies hypovolemia: an abnormally decreased volume of circulating fluid (plasma) in the body.⁶ This code exists to distinguish plasma volume depletion from pure dehydration (E86.0) and from hypovolemic shock (R57.1), enabling precise documentation of fluid status severity and guiding appropriate resource allocation.

Hypovolemia typically results from acute fluid losses (hemorrhage, vomiting, diarrhea, third-spacing) or inadequate intake, and may present with tachycardia, hypotension, elevated BUN/creatinine ratio, and hemoconcentration. ² Key clinical terms include absolute hypovolemia, decreased plasma volume, and prerenal renal failure.

🌳 Code Tree / Hierarchy

E00-E89 Endocrine, nutritional and metabolic diseases ❌ Non-billable
│
├── E70-E88 Metabolic disorders ❌ Non-billable
│ │
│ ├── E86 Volume depletion ❌ Non-billable
│ │ │
│ │ ├── E86.0 Dehydration ✅ Billable
│ │ ├── E86.1 Hypovolemia ◀ THIS CODE ✅ Billable
│ │ └── E86.9 Volume depletion, unspecified ✅ Billable
│ │
│ └── E87 Other disorders of fluid, electrolyte and acid-base balance ❌ Non-billable
│
└── E88 Other metabolic disorders ❌ Non-billable

Document Plasma Volume Loss Explicitly

Payers may scrutinize E86.1 vs E86.0 selection. Ensure provider documentation specifies “hypovolemia,” “plasma volume depletion,” or “intravascular volume loss” rather than generic “dehydration” to support accurate code assignment and avoid downcoding to unspecified E86.9. ⁶⁸

✅ Includes

The following clinical terms and scenarios map to E86.1 when documented:

• Absolute hypovolemia
• Decreased plasma volume
• Extracellular fluid volume depletion
• Prerenal renal failure due to volume loss
• Relative hypovolemia (e.g., vasodilation with inadequate intravascular filling)

❌ Excludes

Excludes 1 — Cannot Be Coded Simultaneously with CODE

Code	Description	Note
P74.1	Dehydration of newborn	Neonatal dehydration is classified separately; use P74.1 for newborns regardless of volume status specifics
T81.19-	Other postprocedural hypovolemic shock	If hypovolemia progresses to shock following a procedure, code the shock (T81.19-) as the primary complication
T79.4-	Traumatic hypovolemic shock	Trauma-induced shock takes precedence; code T79.4- when shock is documented as traumatic in origin

Excludes 1 Violation Risk

Do not report E86.1 with T81.19xx or T79.4xxx when shock is documented—these Excludes1 notes indicate mutual exclusivity. If the provider documents “hypovolemic shock,” code the shock (R57.1 or trauma-specific T-code) and omit E86.1 unless the guideline explicitly permits dual coding (which Excludes1 prohibits). ⁸³

Excludes 2 — May Be Coded in Addition if Separately Present

Code	Description	Note
R57.1	Hypovolemic shock, unspecified	May be coded additionally if the patient has both documented hypovolemia AND progression to shock; sequence based on reason for encounter/admission

📋 Clinical Overview

Hypovolemia vs Dehydration vs Shock: Key Differentiators This table clarifies when to select E86.1 over related volume-depletion codes, critical for accurate severity capture and DRG assignment.

Feature	E86.1 — Hypovolemia	E86.0 — Dehydration	R57.1 — Hypovolemic Shock
Primary Pathophysiology	Loss of plasma volume (water + electrolytes)	Primarily water loss, hypernatremia possible	Hemodynamic collapse due to inadequate perfusion
Typical Etiology	Hemorrhage, severe vomiting/diarrhea, burns, third-spacing	Inadequate intake, fever, diabetes insipidus	Untreated hypovolemia, massive fluid loss, sepsis
Key Clinical Signs	Tachycardia, hypotension, elevated BUN/Cr, hemoconcentration	Dry mucosa, poor skin turgor, hypernatremia	Altered mental status, oliguria, lactic acidosis, refractory hypotension
Coding Priority	Code when plasma depletion documented without shock	Code when water-loss predominates, no shock	Code when shock criteria met; E86.1 may be secondary if documented

CDI Query Trigger — Clarify Volume Status Terminology

When documentation states “dehydration” but clinical findings suggest intravascular depletion (e.g., hypotension responsive to isotonic fluids, elevated BUN/Cr >20:1), query provider: “Does the patient have hypovolemia (plasma volume depletion) versus dehydration (primarily water loss)?” This distinction affects code selection (E86.1 vs E86.0) and may impact DRG weight if associated with MCC-level complications.

Manifestations & Symptom Burden

Common presenting symptoms and associated conditions when E86.1 is documented:

• Hypotension: Systolic BP <90 mmHg or >40 mmHg drop from baseline ⁷⁰
• Tachycardia: Compensatory heart rate elevation >100 bpm
• Acute kidney injury: Prerenal azotemia from reduced renal perfusion
• Electrolyte imbalances: hyponatremia, hypokalemia, or metabolic acidosis requiring E87.- codes

Coding Manifestations

Always code the documented manifestations to fully capture the patient’s complexity. Examples include: E87.1 — Hypo-osmolality and hyponatremia (if documented) N17.9 — Acute kidney injury, unspecified (if prerenal AKI confirmed) R57.1 — Hypovolemic shock (if progression occurs; Excludes2 permits dual coding)

💰 HCC Risk Adjustment (CMS-HCC v28)

Field	Detail
CMS-HCC Model Version	v28 (2024-2025 Implementation)
HCC Assignment	❌ Not Mapped — Acute, non-chronic condition
HCC Category	N/A
RAF Coefficient	~0.00 (no direct contribution)

E86.1 does not map to an HCC under CMS-HCC v28. ⁴⁶

Capture Annually

This section does not apply. E86.1 is an acute condition and not eligible for HCC risk adjustment. Focus documentation efforts on chronic comorbidities that do map to HCCs (e.g., CKD, heart failure) when present concurrently.

🏥 MS-DRG Assignment

MDC 10 — Endocrine, Nutritional & Metabolic Diseases & Disorders

DRG	Title	Est. Relative Weight*
DRG 640	Miscellaneous disorders of nutrition, metabolism, fluids and electrolytes with MCC	~1.3356
DRG 641	Miscellaneous disorders of nutrition, metabolism, fluids and electrolytes with CC	~0.9500 (approximate)
DRG 641	Miscellaneous disorders of nutrition, metabolism, fluids and electrolytes without CC/MCC	~0.7782

Approximate. Verify against IPPS FY2026 Final Rule tables. ²

Sequencing and Complications

When E86.1 is the reason for admission (e.g., severe hypovolemia requiring IV resuscitation), sequence as principal diagnosis grouping to DRG 640/641. When secondary, it may function as a CC if paired with certain principal diagnoses (e.g., gastroenteritis, postoperative state). Associated acute kidney injury (N17.-) or electrolyte disorders (E87.-) often serve as MCCs, upgrading DRG 641 → 640. Avoid sequencing E86.1 as principal when shock (R57.1) or trauma is the primary driver.

🔗 Related ICD-10-CM Codes

Volume Depletion Spectrum — Specificity Variants

Code	Description
E86.1	Hypovolemia ← This Code
E86.0	Dehydration (primarily water loss)
E86.9	Volume depletion, unspecified (use only if specificity unavailable)

Associated Electrolyte & Acid-Base Disorders — Code Additionally When Documented

Code	Description
E87.0	Hyperosmolality and hypernatremia
E87.1	Hypo-osmolality and hyponatremia
E87.2	Acidosis (specify type if documented)
E87.3	Alkalosis

🛠️ Commonly Associated CPT Codes (Internal Medicine / Hospital Setting)

Inpatient and Profee Setting Context

These CPT codes are frequently reported with E86.1 for evaluation, monitoring, or treatment of hypovolemia. Ensure documentation supports medical necessity for each service.

CPT Code	Description	Profee Coding Notes (Modifier 26)
96360	IV infusion, hydration; initial, 31 min-1 hour	Report once per encounter; time must be documented. Bundles with subsequent hydration hours (96361).
96361	IV infusion, hydration; each additional hour	Use with 96360; requires separate time documentation for each additional hour.
99221-99223	Initial hospital care, per day	Select level based on MDM or time; hypovolemia management often supports moderate/high complexity.
99291	Critical care, first 30-74 minutes	Report only if patient meets critical care criteria (e.g., hemodynamic instability requiring vasoactive support).
36415	Collection of venous blood by venipuncture	Separately report only if not bundled into E/M or procedure; often included in global service.

NCCI Bundling Considerations

CPT 96360 billed on the same day as 96361: 96361 is an add-on code and must be reported with 96360; no modifier required. 96360 billed with therapeutic infusion (e.g., 96365): Hydration bundles into therapeutic infusion; do not report 96360 separately unless hydration is substantial and separately identifiable (requires modifier -59 and clear documentation). ⁷⁴

🔬 ICD-10-PCS Crosswalk (Inpatient Procedures)

When E86.1 is an inpatient diagnosis, these PCS codes are relevant for associated inpatient procedures.

PCS Section	Body System	Root Operation	Clinical Application
3 (Administration)	3 (Circulatory)	0 (Introduction)	IV fluid resuscitation for hypovolemia: 3E033GC (Introduction of other fluid into peripheral vein, percutaneous)
3 (Administration)	3 (Circulatory)	0 (Introduction)	Electrolyte replacement infusion: 3E033VZ (Introduction of other substance into peripheral vein, percutaneous)
5 (Extracorporeal)	1 (Physiological Systems)	1 (Assistance)	Continuous renal replacement therapy (CRRT) for hypovolemia-induced AKI: 5A1D00Z

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💊 Coding Scenarios and Examples

Scenario 1 — Outpatient / ED: Acute Gastroenteritis with Hypovolemia

Clinical Vignette: 45-year-old male presents to ED with 2 days of profuse diarrhea and vomiting. BP 92/58 mmHg, HR 118 bpm, dry mucous membranes, BUN/Cr 32/1.2. Provider documents “hypovolemia secondary to gastroenteritis.” Patient receives 1L NS bolus and improves.

Principal Diagnosis: E86.1 — Hypovolemia (documented plasma volume depletion with hemodynamic signs) 2

Secondary Diagnoses: A09 — Infectious gastroenteritis and colitis, unspecified (etiology) E87.1 — Hypo-osmolality and hyponatremia (if labs confirm)

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Scenario 2 — Inpatient: Postoperative Hypovolemia Complicating Recovery

Clinical Vignette: 68-year-old female s/p colectomy develops tachycardia, hypotension on POD#1. Labs show elevated BUN/Cr, hemoconcentration. Provider documents “postoperative hypovolemia requiring IV fluid resuscitation.” No shock criteria met.

Principal Diagnosis: T81.89XA — Other complications of procedures, initial encounter (reason for admission/readmission)

Secondary Diagnoses: E86.1 — Hypovolemia (CC that may increase DRG weight when paired with surgical principal) 2 N17.9 — Acute kidney injury, unspecified (if prerenal AKI documented; potential MCC)

MS-DRG Assignment: Principal T81.89XA with secondary E86.1 and N17.9 may group to DRG 640 (with MCC) rather than lower-weight DRG, reflecting higher resource utilization for fluid/electrolyte management and renal monitoring.

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Scenario 3 — CDI Query: Documentation Specificity Gap

Clinical Vignette: Progress note states “patient is dehydrated, give IV fluids.” Vital signs show hypotension and tachycardia; labs show elevated BUN/Cr ratio. No explicit mention of “hypovolemia” or “plasma volume depletion.”

Action / Outcome: Ambiguity between E86.0 (dehydration) and E86.1 (hypovolemia) creates coding uncertainty. CDI query: “Provider, clinical findings (hypotension, tachycardia, elevated BUN/Cr) suggest intravascular volume depletion. Did you intend to document hypovolemia (plasma volume loss) rather than dehydration (primarily water loss)?”

Query Response: [Provider updates documentation to confirm: “Patient has hypovolemia with prerenal azotemia secondary to inadequate oral intake.“]

Corrected ICD-10-CM Coding: E86.1 — Hypovolemia (final accurate code after CDI clarification) N17.9 — Acute kidney injury, unspecified (supporting manifestation)

⚠️ Coding Pitfalls and Tips

	Pitfall or Tip
❌	Confusing E86.1 with E86.0. Hypovolemia = plasma volume loss (water + electrolytes); dehydration = primarily water loss. Using E86.0 when hypovolemia is documented may understate severity and miss CC/MCC opportunities.
❌	Coding E86.1 with Excludes1 shock codes (T81.19, T79.4). If shock is documented, code the shock per Excludes1 guidance; do not report both.
✅	Always code associated electrolyte disorders (E87.-) when documented. E86.1 includes instruction to “Use additional code(s) for any associated disorders of electrolyte and acid-base balance.”
✅	Document time for hydration infusions (96360/96361) to support billing. NCCI edits bundle hydration with therapeutic infusions; use modifier -59 only with clear documentation of separate service.
✅	Query for specificity when “dehydration” is documented but clinical picture suggests hypovolemia. Precise terminology affects code selection, DRG assignment, and clinical accuracy.

📚 Sources

¹ CMS/NCHS. ICD-10-CM Official Guidelines for Coding and Reporting, FY2026.
² ICD10Data.com. 2026 ICD-10-CM Diagnosis Code E86.1: Hypovolemia. https://www.icd10data.com/ICD10CM/Codes/E00-E89/E70-E88/E86-/E86.1
³ AAPC. ICD-10 Code for Hypovolemia — E86.1. https://www.aapc.com/codes/icd-10-codes/E86.1
⁴ MD Clarity. ICD Diagnosis Code E86.1: What It Is & When to Use. https://www.mdclarity.com/icd-codes/e86-1
⁵ ICDcodes.ai. E86.1: Billable ICD-10 Code for Hypovolemia. https://icdcodes.ai/icd10/E86.1
⁶ Unbound Medicine. E86.1 — Hypovolemia | ICD-10-CM. https://www.unboundmedicine.com/icd/view/ICD-10-CM/940714/all/E86_1___Hypovolemia
⁷ CMS. IPPS Final Rule FY2026 — MS-DRG Definitions Manual v43. MDC 10 logic tables.
⁸ AMA. CPT Professional Edition 2026. Medicine Section — Infusion/Hydration Services.
⁹ CMS. 2025-2026 Medicare Advantage Risk Adjustment — CMS-HCC Model v28 ICD-10-CM Mappings.
¹⁰ SCAI. Understanding NCCI Edits. https://www.scai.org/sites/default/files/2022-07/Understanding%20NCCI.pdf