Essential (primary) hypertension
In Hypertensive diseases (I10-I1A), chapter 9: Diseases of the Circulatory System
- I10 is billable and valid on claims for FY 2027. If the record has more detail, check the other codes under I10-I1A below.
- As a secondary diagnosis it is not a CC or MCC, so it doesn't raise the MS-DRG payment.
- Doesn't count toward a Medicare Advantage risk score (no HCC in V28).
- AHRQ's Chronic Condition Indicator classes it as chronic: expected to last 12 months or longer and to limit daily life or need ongoing care.
- 25,936 US deaths in 2024 had an underlying cause in category I10, per the National Vital Statistics System on CDC WONDER. Death records use WHO ICD-10, so the count is for the whole category.
- Medicare questions an inpatient admission when this is the principal diagnosis. (Questionable Admission list)
Also indexed as: Hypertension
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Instructional notes
Includes: conditions that are coded here
- high blood pressure
- hypertension (arterial) (benign) (essential) (malignant) (primary) (systemic)
Excludes1: not coded here, use a different code
Also applies, from Hypertensive diseases (I10-I1A)
These notes sit on I10-I1A and apply to every code under it, including I10.
Excludes1: not coded here, use a different code
Excludes2: not included here, code separately if applicable
Official coding guidelines
From the ICD-10-CM Official Guidelines for Coding and Reporting, FY 2027 (CMS and NCHS). Links open the PDF at the right page.
- Section I.C.9.a Hypertension (page 50), covers I10
Presume hypertension is linked to heart disease and CKD unless documented as unrelated: use I11, I12, or I13 with additional I50 or N18 codes as directed. Other conditions need provider-documented linkage to be coded as related.
Other Chapter 9 topics:
Other codes under I10-I1A
Hypertensive diseases (I10-I1A)
- I10Essential (primary) hypertension(this code)
- I11Hypertensive heart disease
- I12Hypertensive chronic kidney disease
- I13Hypertensive heart and chronic kidney disease
- I15Secondary hypertension
- I16Hypertensive crisis
- I1AOther hypertension
I10 MS-DRGs
As the principal diagnosis, I10 groups to MS-DRG 304 or 305 (v44.0). Which one applies depends on procedures performed, secondary diagnoses (CC/MCC), and the patient's age and discharge status.
Related conditions
Grouped by AHRQ's Clinical Classifications Software Refined (CCSR), which sorts every diagnosis code into clinically meaningful categories.
I10 is in Essential hypertension (CIR007, its default category), with 19 codes. Others in it:
- O10.011 Pre-existing essential hypertension complicating pregnancy, first trimester
- O10.012 Pre-existing essential hypertension complicating pregnancy, second trimester
- O10.013 Pre-existing essential hypertension complicating pregnancy, third trimester
- O10.019 Pre-existing essential hypertension complicating pregnancy, unspecified trimester
- O10.02 Pre-existing essential hypertension complicating childbirth
- O10.03 Pre-existing essential hypertension complicating the puerperium
- O10.911 Unspecified pre-existing hypertension complicating pregnancy, first trimester
- O10.912 Unspecified pre-existing hypertension complicating pregnancy, second trimester
Medicare coverage articles listing I10
These 25 Medicare billing and coding articles list I10 as a diagnosis that supports medical necessity for the services they cover. From the CMS Medicare Coverage Database; check your own contractor's article before billing.
- MolDX: Biomarkers in Cardiovascular Risk Assessment (4 contractors)
- MolDX: Biomarker Testing in Metabolic Dysfunction-Associated Steatotic Liver Disease and Metabolic Dysfunction-Associated Steatohepatitis (3 contractors)
- Cardiac Catheterization and Coronary Angiography (2 contractors)
- Magnetic Resonance Angiography (MRA) (2 contractors)
- Non-Invasive Vascular Studies (2 contractors)
- Pharmacogenomics Testing (2 contractors)
- Transthoracic Echocardiography (TTE) (2 contractors)
- Aortography and Peripheral Angiography
- Bariatric Surgery Coverage
- Bariatric Surgery for Treatment of Co-Morbidities Conditions Related to Morbid Obesity
And 15 more.
Other codes that refer to I10
Notes on these codes point to I10.
- G31.84 Use Additional Code: hypertension (I10-I1A)
- H35.0 Code Also: any associated hypertension (I10)
- I16 Code Also: any identified hypertensive disease (I10-I15, I1A)
- I1A.0 Code First: essential hypertension (I10)
- I20-I25 Code Also: the presence of hypertension (I10-I1A)
- I60-I69 Use Additional Code: hypertension (I10-I1A)
- I67.4 Code Also: essential (primary) hypertension (I10)
- I87.2 Code Also: essential (primary) hypertension (I10)
- O10.0 Includes: Any condition in I10 specified as a reason for obstetric care during pregnancy, childbirth or the puerperium
- Z15.3 Code Also: if applicable, hypertension (I10-I1A)
About the condition
Plain-language background from MedlinePlus (National Library of Medicine), not coding guidance.
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. This is called diastolic pressure.
Read more about high blood pressure on MedlinePlusCode history
Valid since FY2016, when ICD-10-CM took effect on October 1, 2015.
ICD-9-CM equivalent
Legacy crosswalk from the CMS General Equivalence Mappings (last updated 2018).
- 401.0 Malignant essential hypertension (approximate)
- 401.1 Benign essential hypertension (approximate)
- 401.9 Unspecified essential hypertension (approximate)