Who Are The Major Health Insurance Companies? 
There 's many many insurance companies out there in the marketplace . United Health Group -LRB- includes United Healthcare -RRB- is the biggest health insurance company in the United States and offer plans in every state . Wellpoint -LRB- includes Anthem -RRB- Kaiser , Aetna , Cigna , Coventry , and CareFirst are some of the other big name insurance companies in the country . However , not every company offers health plans in every state . 