Aetna Inc. (/??tn?/) is an American managed health care company that sells traditional and consumer directed health care insurance and related services, such as medical, pharmaceutical, dental, behavioral health, long-term care, and disability plans, primarily through employer-paid (fully or partly) insurance and benefit programs, and through Medicare. Since November 28, 2018, the company has been a subsidiary of CVS Health. The company’s network includes 22.1 million medical members, 12.7 million dental members, 13.1 million pharmacy benefit management services members, 1,200,000 health-care professionals, over 690,000 primary care doctors and specialists, and over 5,700 hospitals.[2] Aetna is the direct descendant of Aetna (Fire) Insurance Company of Hartford, Connecticut.[3] The name of the company is based on Mount Etna, at the time the most active volcano in Europe.

American International Group, Inc., also known as AIG, is an American multinational finance and insurance corporation with operations in more than 80 countries and jurisdictions. As of December 31, 2016, AIG companies employed 56,400 people.[4] The company operates through three core businesses: General Insurance, Life & Retirement, and a standalone technology-enabled subsidiary.[5][6][7] General Insurance includes Commercial, Personal Insurance, U.S. and International field operations. Life & Retirement includes Group Retirement, Individual Retirement, Life, and Institutional Markets.[5][6][7] AIG’s corporate headquarters are in New York City and the company also has offices around the world. AIG serves 87% of the Fortune Global 500 and 83% of the Forbes 2000.[8] AIG was ranked 60th on the 2018 Fortune 500 list.[9] According to the 2016 Forbes Global 2000 list, AIG is the 87th largest public company in the world.[10] On December 31, 2017, AIG had $65.2 billion in shareholder equity.[11] During the financial crisis of 2008, the Federal Reserve bailed the company out for $180 billion and assumed control, with the Financial Crisis Inquiry Commission correlating AIG’s failure with the mass sales of unhedged insurance.[12] In 2011 the nationalization of AIG was ruled illegal,[13] and after regaining autonomy, AIG repaid $205 billion to the United States government in 2012.

American Family Insurance, also abbreviated as AmFam, is an American private mutual company that focuses on property, casualty, and auto insurance, and also offers commercial insurance, life, health, and homeowners coverage as well as investment and retirement-planning products. A Fortune 500 company, its revenues were over $9.5 billion in 2017.[3][4] It should not be confused with American Family Home Insurance Company, a subsidiary of Munich Re subsidiary American Modern Insurance Group, Inc., or American Family Life Assurance Company of Columbus.

Anthem, Inc., is a provider of health insurance in the United States. It is the largest for-profit managed health care company in the Blue Cross Blue Shield Association. As of 2018, the company had approximately 40 million members.[2] Anthem is ranked 33rd on the Fortune 500.[3] Prior to 2014, it was named WellPoint, Inc.[4][5] The company was formed by the 2004 merger of WellPoint, based in California, and Anthem, based in Indianapolis, after both companies acquired several health insurance companies. The company operates as Anthem Blue Cross in California, where it has about 800,000 customers and is the largest health insurer. It operates as Empire BlueCross BlueShield in New York State and as Anthem Blue Cross and Blue Shield in 10 states.

Assurant, Inc. is a global provider of risk management products and services[3] with headquarters in New York City.[4] Its businesses provide a diverse set of specialty, niche-market insurance products in the property, casualty, extended device protection, and preneed insurance sectors. The company’s three operating segments are Global Housing, Global Lifestyle, and Global Preneed.[4] The company, formerly known as Fortis, Inc., was spun off from Dutch and Belgian financial-services company Fortis Insurance N.V. in 2004. The company’s initial public offering on Feb. 5, 2004 at $1.76 billion was the fourth largest that year. In connection with the public offering, the company changed its name to Assurant, Inc.[5][6] Assurant is 440 on the Fortune 500 list of the largest publicly traded companies in the United States.

Cigna is an American worldwide health services organization based in suburban Bloomfield, Connecticut and Philadelphia, Pennsylvania.[2] Its insurance subsidiaries are major providers of medical, dental, disability, life and accident insurance and related products and services, the majority of which are offered through employers and other groups (e.g. governmental and non-governmental organizations, unions and associations). Cigna is incorporated in Connecticut. [3] Cigna offers Medicare and Medicaid products and health, life and accident insurance coverages primarily to individuals in the U.S. and selected international markets. In addition to its ongoing operations described above, Cigna also has certain run-off operations, including a Run-off Reinsurance segment.[4] In the Phoenix metropolitan area, Cigna runs a full-service staff-model HMO (health maintenance organization) with satellite clinics throughout the region, known as the Cigna Medical Group.[5] Cigna Global Health Benefits also operates under the Cigna corporation. Cigna’s motto is ‘Together, all the way.'[6] The company ranked No. 73 in the 2018 Fortune 500 list of the largest United States corporations by total revenue.[7] On March 7, 2018, it was announced that Cigna would buy Express Scripts in a $67 billion deal[8][9] and on August 24, 2018, the shareholders of Cigna and Express Scripts approved the deal.

Farmers Insurance Group (informally Farmers) is an American insurer group of automobiles, homes and small businesses and also provides other insurance and financial services products. Farmers Insurance has more than 48,000 exclusive and independent agents and approximately 21,000 employees. It is a subsidiary of the Swiss company Zurich Insurance Group.

Humana Inc. is a for-profit American health insurance company based in Louisville, Kentucky. As of 2014 Humana had over 13 million customers in the U.S.,[2] reported a 2013 revenue of US$41.3 billion,[3] and had 51,600 employees.[4] In 2018, the company ranked 56 on the Fortune 500 list,[5] which made it the highest ranked (by revenues) company based in Kentucky. It has been the third largest health insurance in the nation.[6] The U.S. Dept. of Health and Human Services investigated Humana in 2009 for sending flyers to Medicare recipients that the AARP characterized as deceptive. The company’s managed care model has also been criticized for ethical lapses and limitations. The health insurer Aetna said on July 3, 2015, that it had agreed to acquire its smaller rival Humana for $37 billion in cash and stock[7] but walked away from the deal after a court ruling that the merger would be anti-competitive.

Lincoln National Corporation is a Fortune 250 American holding company, which operates multiple insurance and investment management businesses through subsidiary companies. Lincoln Financial Group is the marketing name for LNC and its subsidiary companies. LNC was organized under the laws of the state of Indiana in 1968, and maintains its principal executive offices in Radnor, Pennsylvania.[3] The company traces its roots to its earliest predecessor founded in 1905. In addition, LNC is the naming rights sponsor of Lincoln Financial Field in Philadelphia, home field of the Philadelphia Eagles of the National Football League.

MetLife, Inc. is the holding corporation for the Metropolitan Life Insurance Company (MLIC),[2] better known as MetLife, and its affiliates. MetLife is among the largest global providers of insurance, annuities, and employee benefit programs, with 90 million customers in over 60 countries.[3][4] The firm was founded on March 24, 1868.[5] MetLife ranked No. 43 in the 2018 Fortune 500 list of the largest United States corporations by total revenue.[6] On January 6, 1915, MetLife completed the mutualization process, changing from a stock life insurance company owned by individuals to a mutual company operating without external shareholders and for the benefit of policyholders.[7] After 85 years as a mutual company, MetLife demutualized into a publicly traded company with an initial public offering in 2000.[8] Through its subsidiaries and affiliates, MetLife holds leading market positions in the United States, Japan, Latin America, Asia’s Pacific region, Europe, and the Middle East.[9] MetLife serves 90 of the largest Fortune 500 companies.[10] The company’s principal offices are located at 200 Park Avenue, New York City in Midtown Manhattan, New York City, though it retains some executive offices and its boardroom in the MetLife Building, located at 200 Park Avenue, New York City, which it sold in 2005.[11] In January 2016, the company announced that it would spin off its U.S. retail business, including individual life insurance and annuities for the retail market, in a separate company called Brighthouse Financial, which launched in March 2017.[12] The continuing MetLife company kept naming rights to MetLife Stadium in northern New Jersey.