ICD-10 Code I10 – Essential (primary) hypertension (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I10 – Essential (primary) hypertension
What it is
I10 identifies primary, or essential, hypertension: persistently elevated blood pressure without a known secondary cause. Use it when the record states hypertension and no underlying condition is documented.
Clinical signs
Many patients have no symptoms, and the finding is often documented from repeated elevated blood pressure measurements. Clinical features vary; refer to documentation.
When to use this code
Use I10 when the provider documents essential hypertension, primary hypertension, or hypertension NOS without linking it to another disorder. It also applies when the chart shows chronic hypertension and no secondary cause is identified. Code the condition as documented, even if the visit is for another reason.
Do not use for
Do not use I10 for secondary hypertension caused by another disease, pregnancy-related hypertension, or transient elevated readings without a diagnosis. Check documentation if the record suggests a different hypertensive disorder.
Coding tip
Look for wording such as “essential,” “primary,” or plain “hypertension” before assigning I10.