UnitedHealthcare earned five stars for value for price in our survey, and 92 percent of customers plan to renew. UnitedHealthcare is a part of UnitedHealth Group, the second-largest health insurance carrier in the country, according to SNL Financial, and serves about 70 million people. UnitedHealth is based in Minnetonka, Minnesota. It is No. 14 on Fortune’s list of top 500 companies in the United States. It was founded in 1977 and is a publicly traded company.