The primary ICD-10-CM code for essential hypertension is I10 (Essential (primary) hypertension), a billable code reported when hypertension is primary and not attributable to an identifiable secondary cause.
Primary codes
Billable
Billable
Extension
—
7th character
—
POA exempt
No
Includes
- high blood pressure
- hypertension (arterial) (benign) (essential) (malignant) (primary) (systemic)
Type 1 excludes
Coding risks
- Pairing with a mutually-exclusive code (Excludes-1 violation)
Hierarchy
Code ranges
Essential (primary) hypertension
Single category covering high arterial blood pressure without identified secondary cause, including benign, malignant, and unspecified essential hypertension presentations.
Hypertensive diseases
Encompasses essential hypertension and hypertensive disease of the heart, kidney, and combined organs, plus secondary and other specified hypertensive conditions.
Hypertensive heart disease
Captures hypertension with associated heart failure or other heart involvement attributed by the provider to the hypertensive state.
Hypertensive chronic kidney disease
Reports hypertension with chronic kidney disease where a causal relationship is presumed under ICD-10-CM coding conventions.
Secondary hypertension
Hypertension attributable to an identifiable underlying cause such as renovascular disease, endocrine disorders, or other specified secondary etiologies.
Coding risks
Avoid these common coding issues when reporting Essential Hypertension.
Impact
Assigning I10 without ruling out secondary causes may miscode true secondary hypertension (I15) as essential.
Mitigation
Consider querying the provider when renal, endocrine, or drug-induced etiology appears in the chart.
Related codes
Ancillary and co-coding
Codes commonly reported with the primary diagnosis on the same claim.
Z-code variants
Family history, personal history, or screening encounter codes related to this condition.
In pregnancy
Pregnancy-specific O-code adaptations used in place of the primary when the condition occurs during or complicates pregnancy.
Differential codes
Alternative or commonly confused codes to consider when documentation suggests a different condition than the primary diagnosis.
Frequently asked questions
Yes, when both are documented. I10 and I15 codes are not Excludes1; sequence per the underlying etiology guidance.
References
Compiled from the following authoritative coding references. Last updated 2026-05-15.