ICD-10 Code I15.9 – Secondary Hypertension, Unspecified (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I15.9 – Secondary hypertension, unspecified
What it is
I15.9 identifies secondary hypertension when the cause is not specified in the record. Use it for elevated blood pressure attributed to another condition, but without a documented underlying cause.
Clinical signs
Clinical features vary; refer to documentation. You may see hypertension described as secondary, with signs of an associated disorder, but the record does not name the specific cause.
When to use this code
Use I15.9 when the provider documents secondary hypertension and does not identify the underlying condition. It is appropriate when hypertension is clearly linked to another cause, but the cause remains unspecified in the note.
If the record names a specific secondary cause, code that condition instead of this unspecified category. Check documentation for any additional diagnosis that explains the hypertension.
Do not use for
Do not use this code for primary, essential hypertension. Also avoid it when the underlying cause of secondary hypertension is documented and a more specific code is available.
Coding tip
Query for the cause whenever secondary hypertension is documented but not explained.