The CDC has found that nearly 90% of adults in the United States with uncontrolled hypertension have a usual source of healthcare and insurance. About 66.9 million adults had hypertension from 2003 to 2010. Among these individuals:

14.1 million were not aware of their hypertension.
5.7 million were aware but not receiving pharmacologic treatment.
16.0 million were aware and being treated with medication.

Abstract: Morbidity & Mortality Weekly Report, September 7, 2012.