The 5 Biggest Health Insurers in the US

Surprising facts and statistics you may not know

Woman handing over insurance card at medical office

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There are are a plethora of health insurance companies in the United States. Many of the provide manage smaller regional areas, either independently or as part of the Health Insurance Marketplace, while others offer coverage in all 50 states.

There is also Medicaid, Medicare, and the Children's Health Insurance Program (CHIP), three government-run programs that cover more than 140 million Americans, according to the Centers of Medicare and Medicaid Services (CMS).

Nearly the same number of Americans get private insurance through 5 health insurance giants, either directly or through corporate subsidiaries. Here is an overview of who they are and what they offer:


Anthem was created from the merger of WellPoint Health Networks and Anthem, Inc. in 2004. Headquartered in Indianapolis, Indiana, Anthem is an independent licensee of the Blue Cross and Blue Shield Association serving members in California, Colorado, Connecticut, Georgia, Indiana, Kentucky, Maine, Missouri, Nevada, New Hampshire, New York, Ohio, Virginia, and Wisconsin. As of 2018, its total medical membership was 39.9 million.

Anthem operates in certain markets under the names Anthem Blue Cross, Anthem Blue Cross and Blue Shield, Blue Cross and Blue Shield of Georgia, Empire Blue Cross Blue Shield, or Empire Blue Cross (in the New York service areas). Anthem also serves customers throughout the country as UniCare. All told, Anthem insures one in nine Americans.

Anthem’s managed care plans include:

Affiliated companies provide an array of specialty products and services such as life and disability insurance benefits, dental, vision, behavioral health benefit services, radiology benefit management, analytics-driven personal health care guidance, long-term care insurance, and flexible spending accounts.

Anthem was one of the leading opponents of the Affordable Care Act and, according to the Los Angeles Times, asked employees in Calfornia to oppose the legislation in contravention to state laws forbidding such practices.

Cigna Health

Headquartered in Philadelphia, Cigna's history stretches back more than 125 years. The company has more than 3.6 million insurees in the United States and another 8 million in 29 other countries.

In addition to private health insurance, Cigna offers Medicare and Medicaid products as well as life and accident insurance both in the United States and select international markets.

Cigna has three divisions:

  • Cigna HealthCare provides health plans and services to companies and individuals, offering medical, dental, behavioral health, pharmacy, and vision care coverage.
  • Cigna Group Insurance is one of the top providers of group disability, life, and accident coverage in the United States.
  • Cigna International provides life, accident, and supplemental health insurance as well as specialized health products to employees of multinational companies based abroad.

In July 2015, Cigna was meant to merge with Anthem, but the effort was abandoned in 2017 after the U.S. Department of Justice blocked the move in a highly publicized antitrust trial.


Aetna was founded in 1853 in Hartford, Connecticut and provides healthcare, dental, pharmacy, group life, and disability insurance, among other proprietary products. Aetna today boasts approximately 22.1 million medical members, 12.7 million dental members, and 13.1 million pharmacy members.

The insurer provides benefits through employers in all 50 states, with products and services targeted specifically to small, mid-sized, and multi-site national employers. Aetna also serves Medicare and Medicaid beneficiaries in some markets.

In 2008, Aetna filed a $4.8 billion correction with health insurance regulators which revealed that the insurer spent far less on small business health plans than previously reported.


Founded in 1961 and headquartered in Louisville, Kentucky, Humana began as a single nursing home and grew to more than 100 hospitals before getting involved in health insurance. Humana has 16.6 million medical members and is consistently listed on Fortune's Top 100 companies based on annual revenue.

Humana offers a wide range of services and plans including:

  • Humana Medicare [lans
  • Humana One (individual insurance with a range of benefits)
  • Humana One Dental and Vision
  • Humana One Life and Supplemental Insurance
  • HumanaVisionCare

The insurer also offers a pharmacy benefit manager (PBM), called Humana Pharmacy Solutions, which is one of the highest-volume operations of its kind in the country.

Humana participated in an effort to block the Affordable Care Act in 2009 by sending letters to elderly Medicare recipients claiming that their core Medicare benefits could be cut by the Obama administration's healthcare reform.


UnitedHealthcare is an operating division of UnitedHealth Group, the largest single health carrier in the United States. The company was formed in 1977 through the reorganization of Charter Med, Inc., a company established in 1974.

UnitedHealthcare provides products and services to some 70 million Americans, while its pharmaceutical management programs provide drugs for 13 million adults and children.

UnitedHealthcare has three divisions:

  • UnitedHealthcare Employer & Individual provides benefit plans and service programs to large national employers and coordinates network-based health care benefits on behalf of small to mid-sized employers, individuals, students, and families.
  • UnitedHealthcare Medicare & Retirement is the largest insurance model dedicated to meeting the needs of seniors.
  • UnitedHealthcare Community & State is designed to provide healthcare services for state-sponsored public health programs, including Medicaid.

In 2018, UnitedHealthcare received the number 1 ranking in the insurance and managed care category on Fortune’s list of the World’s Most Admired Companies, a feat the company has repeated regularly.

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Article Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial policy to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Centers for Medicare & Medicaid Services. CMS Fast Facts

  2. Aetna. Aetna Facts

  3. Humana 2018 Annual Report

  4. Fortune. World's Most Admired Companies

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