Cigna and AETNA are two of the biggest names in health plans. Cigna is an American health services organization that provides health insurance, employee benefits, and other services to over 95 million customers worldwide. AETNA is a Fortune 500 healthcare company that provides health insurance products and services to over 22 million people in the United States. Both companies offer a variety of health plans, including individual, family, and group plans, as well as Medicare and Medicaid plans.