ICD-10 Code I27.0 – Primary pulmonary hypertension (2026): Diagnosis, Symptoms & Billing Guide
2026 ICD-10-CM Diagnosis Code I27.0 – Primary pulmonary hypertension
What it is
I27.0 identifies primary pulmonary hypertension, a form of pulmonary arterial hypertension that is not explained by another known condition. Use it when the record documents this specific diagnosis.
Clinical signs
Clinical features vary; refer to documentation. Commonly documented findings include shortness of breath, fatigue, chest discomfort, syncope, or evidence of elevated pulmonary artery pressure on evaluation.
When to use this code
Use I27.0 when the provider clearly states primary pulmonary hypertension or idiopathic pulmonary arterial hypertension. It is appropriate for confirmed encounters, problem lists, and follow-up visits when the condition remains active. Check documentation if the cause is secondary or unspecified.
Do not use for
Do not use this code for pulmonary hypertension due to another disease, such as left heart disease, lung disease, or chronic thromboembolic disease. If the record does not specify primary disease, check documentation.
Coding tip
Verify that the note supports a primary diagnosis, because secondary pulmonary hypertension requires a different code.