Humana Inc. is a Louisville, Kentucky-based for-profit health insurance company. As of 2014 Humana has had over 13 million customers in the U.S., reported a 2013 revenue of US$41.3 billion, and has had over 52,000 employees. In 2013, the company ranked 73 on the Fortune 500 list, which made it the highest ranked (by revenues) company based in Kentucky. It has been the third largest health insurance in the nation.The U.S. Dept.