I10 Essential (primary) hypertension

The ICD-10-CM code for Essential (primary) hypertension is I10 (FY2026). It is a billable, claim-ready diagnosis code.

Choosing between codes? See the guide: ICD-10 code for hypertension.

Classification

Chapter

9: Diseases of the circulatory system (I00-I99)

Section

I10-I1A: Hypertensive diseases (I10-I1A)

Category I10

1 code (1 billable)

FY2026 Status

Stable since FY2024

Also Known As

ICD-10-CM Alphabetic Index entries that lead to I10:

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

U.S. Hospital Utilization

• An estimated 8,948,026 U.S. inpatient stays in 2023 included I10 among the documented diagnoses.
• 6,465 stays listed it as the principal diagnosis.

Source: National Inpatient Sample (NIS), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality, 2016–2023. National survey-weighted estimates.

Prevalence & Statistics

• Nearly half of U.S. adults — 48.1%, or 119.9 million people — have high blood pressure, defined as systolic pressure above 130 mm Hg, diastolic pressure above 80 mm Hg, or taking medication for high blood pressure (NHANES 2017–March 2020). (CDC — High Blood Pressure Facts, 2017–March 2020 (NHANES))

Official Coding Guidelines

Code separately if documented unrelated; assign I10 or I15; sequence per encounter

The same heart conditions (I50.-, I51.4-I51.7, I51.89, I51.9) with hypertension are coded separately if the provider has documented they are unrelated to the hypertension. The applicable hypertension code I10, Essential (primary) hypertension, or a code from category I15, Secondary hypertension, should be assigned. Sequence according to the circumstances of the admission/encounter.

Use H35.0 with I10-I15 to include systemic HTN; sequencing per reason

Subcategory H35.0, Background retinopathy and retinal vascular changes, should be used along with a code from categories I10 - I15, in the Hypertensive diseases section, to include the systemic hypertension. The sequencing is based on the reason for the encounter.

Source: CMS — ICD-10-CM Official Guidelines for Coding and Reporting, FY2026

References

• CMS — ICD-10-CM Official Code Set and Guidelines, FY2026
• CDC/NCHS — ICD-10-CM Files and Browser Tool
• AHRQ — HCUP National Inpatient Sample, Frequencies by Diagnosis Code (2016–2023)
• CDC — High Blood Pressure Facts (2017–March 2020 (NHANES))