6.United Health Group:

Moving up the list the United Health Group works from Minnesota and works primary in health care plans. The subsidiaries under United Health Care which are Optum and United Healthcare both specialize in health care services. The company’s combined provide average revenue of $ 13 Billion which has been recently reported in 2016. Besides an interest in insurance the company strives at customer satisfaction and has been acclaimed as the “Best health plan provider” in 2010 while in 2011 the company came again for its satisfaction with its employees inside the company works.