2026 ICD-10-CM Diagnosis Code I10Essential (primary) hypertension

ICD-10-CM Codes›I00–I99›I10-I1A›primary

ICD-10-CM I10
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

I10 is a billable ICD-10-CM diagnosis code for essential (primary) hypertension. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 304 through 305. The code is flagged as a questionable admission, since it rarely justifies inpatient admission on its own. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Essential hypertension.

This medical diagnosis code is frequently used in Family Practice, Internal Medicine, Cardiology, and OB/GYN medical specialties to designate conditions such hypertension.

Code Identity

ICD-10-CM Code
I10
Billable Status
Yes — Valid for Submission
Code Describes
Essential (primary) hypertension
Short Description
Essential (primary) hypertension
Same as the full description in the CMS dataset.
Chapter
I10-I1A
Hypertensive diseases

Code Classification

ChapterI00–I99Diseases of the circulatory system
SectionI10-I1AHypertensive diseases
CategoryprimaryEssential hypertension (I10)
This CodeI10Essential (primary) hypertension

Code EditsBilling

Medicare Code Editor checks that affect claim validity for I10.

Questionable admission codes
Some diagnoses are not usually sufficient justification for admission to an acute care hospital. For example, if a patient is given code R030 for elevated blood pressure reading, without diagnosis of hypertension, then the patient would have a questionable admission, since elevated blood pressure reading is not normally sufficient justification for admission to a hospital. The following list contains diagnosis codes identified as questionable admission when used.

Quality Payment Program MeasuresBilling

Medicare quality measures that can apply when I10 is part of the patient record.

Controlling High Blood Pressure

High Priority: YES

Measure Type: Intermediateoutcome

Submission Methods: Claims, Electronic Health Record, Cms Web Interface, Registry

Description: Percentage of patients 18-85 years of age who had a diagnosis of essential hypertension starting before and continuing into, or starting during the first six months of the measurement period, and whose most recent blood pressure was adequately controlled (<140/90mmHg) during the measurement period.

View Measure

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Benign essential hypertension
  • Benign hypertension
  • Brachydactyly and arterial hypertension syndrome
  • Brachydactyly syndrome type E
  • Cerebrovascular accident with intracranial hemorrhage
  • Dementia due to hemorrhagic cerebral infarction due to hypertension
  • Dementia due to hypertensive encephalopathy
  • Dementia due to metabolic abnormality
  • Diastolic hypertension
  • Diastolic hypertension and systolic hypertension
  • Essential hypertension
  • Good hypertension control
  • Grange syndrome
  • Headache due to arterial hypertension
  • Hemorrhagic cerebral infarction
  • Hemorrhagic cerebral infarction due to hypertension
  • Hemorrhagic infarction
  • Hereditary dysplasia of blood vessel
  • High-renin essential hypertension
  • Hypertension monitoring offer default
  • Hypertension monitoring status
  • Hypertension stage 1
  • Hypertension stage 2
  • Hypertension with albuminuria
  • Hypertensive complication
  • Hypertensive crisis
  • Hypertensive disorder
  • Hypertensive emergency
  • Hypertensive optic neuropathy
  • Hypertensive treatment changed
  • Intermittent hypertension
  • Labile diastolic hypertension
  • Labile essential hypertension
  • Labile systemic arterial hypertension
  • Low-renin essential hypertension
  • Malignant essential hypertension
  • Malignant hypertension
  • Martorell ulcer of lower leg
  • Martorell ulcer of lower limb
  • On treatment for hypertension
  • Rebound hypertension
  • Stable hypertension
  • Supine hypertension
  • Sustained diastolic hypertension
  • Systolic essential hypertension
  • Systolic hypertension
  • Transient hypertension

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Includes

  • high blood pressure
  • hypertension (arterial) (benign) (essential) (malignant) (primary) (systemic)

Type 1 Excludes

  • hypertensive disease complicating pregnancy, childbirth and the puerperium O10 O11 O13 O16

Type 2 Excludes

  • essential primary hypertension involving vessels of brain I60 I69
  • essential primary hypertension involving vessels of eye H35.0

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.

    • Hypertension, hypertensive(accelerated) (benign) (essential) (idiopathic) (malignant) (systemic)

Clinical ClassificationClinical

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

CCSR CIR007
Essential hypertension
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Essential Hypertension

    hypertension that occurs without known cause, or preexisting renal disease. associated polymorphisms for a number of genes have been identified, including agt, gnb3, and ece1. omim: 145500

  • Hypertensive Crisis

    a severe, acute increase in blood pressure that may result in stroke or myocardial ischemia.

  • Benign Essential Hypertension

    a condition of mild to moderate high blood pressure that has no identifiable cause.

  • Diastolic Hypertension

    hypertension characterized diastolic blood pressure greater than 90 mmhg on two occasions.

  • Systolic Hypertension

    abnormally high systolic blood pressure.

  • Malignant Hypertension

    severe hypertension that is characterized by rapid onset of extremely high blood pressure.

  • Malignant Essential Hypertension

    essential hypertension with rapid progression to severe high blood pressure, papilledema, and renal failure.

Patient EducationClinical

High Blood Pressure

Blood pressure is the force of your blood pushing against the walls of your arteries. Each time your heart beats, it pumps blood into the arteries. Your blood pressure is highest when your heart beats, pumping the blood. This is called systolic pressure. When your heart is at rest, between beats, your blood pressure falls.

The full article covers:

  • What is blood pressure?
  • How is high blood pressure diagnosed?
  • What are the different types of high blood pressure?
  • Why do I need to worry about high blood pressure?
  • What are the treatments for high blood pressure?

Read the full article at MedlinePlus

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

Convert I10 to ICD-9-CMHistory

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

ICD-9-CM
401.0 Malignant hypertension
Approximate The match is approximate rather than exact.
ICD-9-CM
401.1 Benign hypertension
Approximate The match is approximate rather than exact.
ICD-9-CM
401.9 Hypertension NOS
Approximate The match is approximate rather than exact.

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 I10Overview

Is I10 (Essential (primary) hypertension) a billable code?

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

What MS-DRG does I10 group to?

When essential (primary) hypertension is the principal diagnosis on an inpatient stay, it groups to MS-DRG 304, 305, with relative weights from 0.7551 to 1.1900 depending on complications. Higher weights mean higher Medicare reimbursement.

Does I10 justify an inpatient admission?

Not on its own. The Medicare Code Editor lists this code as a questionable admission because essential (primary) hypertension is not usually sufficient justification for admission to an acute care hospital.

What is the ICD-9 equivalent of I10?

Under the General Equivalence Mappings, essential (primary) hypertension converts to ICD-9-CM 401.0 (malignant hypertension), 401.1 (benign hypertension), and 401.9 (hypertension NOS). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.