The top health insurers by market share are UnitedHealth Group, Anthem, Centene, Humana and Health Care Service Corp. (HCSC). Together these companies control nearly 46% of the health insurance market.

All of these providers offer basic health insurance products to individuals and companies, along with other services that can include Medicaid and Medicare policies, long-term care insurance, dental insurance and vision benefits.

  • What are the biggest health insurance companies?
  • Top 5 largest health insurance companies by membership
  • Largest major medical provider by state
  • Health insurance company rankings by revenue

What are the biggest health insurance companies?

The biggest health insurance companies in the United States include well-known insurance providers. These companies offer a range of products, including individual and group health plans, Medicaid and Medicare policies, and dental and vision benefits.

Market share of largest health insurance companies

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Top 5 largest health insurance companies by membership

The largest health insurance provider can be defined as the company that has the highest number of members. Also called covered lives, membership means the number of individuals who are enrolled in a health insurance plan with that provider. You can enroll in a health insurance policy in many different ways. For example, your employer's benefit plan may offer health insurance coverage. Other ways include:

  • Medicare and retirement plans
  • Medicaid services
  • Individual health insurance (through open enrollment)

1. UnitedHealth Group

UnitedHealthcare, part of UnitedHealth Group, is the largest health insurance company by total members. UnitedHealthcare offers a variety of products from individual health insurance to full employer benefit plans for some of the biggest corporations. Furthermore, its policies can be purchased in all 50 states. UnitedHealthcare is headquartered in Minnetonka, Minn.

Along with having the most members, UnitedHealthcare also has a network of over 1.3 million physicians and health care professionals, with more than 6,500 hospitals. This means that if you have UnitedHealthcare, you will have many options to choose from to receive care.

2. Anthem

Anthem is the second-largest medical insurance provider by total members, with more than 45 million members. The company's Commercial and Business health care segment offers network-based care to large and small businesses, individuals and Medicaid and Medicare markets.

Anthem is part of the Blue Cross Blue Shield Association. This means that when searching for Anthem policies on your state marketplace exchange, you may find products with the BCBS name, but you will be buying from Anthem.

The company currently operates in California, Colorado, Connecticut, Georgia, Indiana, Kentucky, Maine, Missouri, Nevada, New Hampshire, New York, Ohio, Virginia and Wisconsin.

3. Aetna

Aetna was acquired by CVS Health Corp. in 2018. CVS Health now operates the company and has been able to seamlessly integrate its provider networks with Aetna's membership base. Founded in 1853, Aetna is the third-largest provider of health insurance and services, by membership. However, much of its membership comes from providing health insurance to employers and their employees in the private market. Aetna returned to a limited number of ACA marketplaces for the 2022 plan year.

4. Cigna

Cigna is the fourth-largest major medical insurance company in the United States. Headquartered in Bloomfield, Conn., Cigna offers health insurance and health services to companies throughout the world. In addition to corporate health insurance policies and management of those plans, Cigna also offers dental, behavioral health, vision, supplemental health and Medicare/Medicaid benefits.

Cigna currently offers individual health insurance in 13 states: Arizona, Colorado, Florida, Georgia, Illinois, Kansas, Mississippi, Missouri, North Carolina, Pennsylvania, Tennessee, Utah and Virginia. Cigna also provides Medicare Advantage plans in 16 states and Washington, D.C.

5. Humana

Humana comes in as the fifth-largest health insurance company by membership. The provider was founded in 1961 and originally sold long-term care insurance before expanding into selling health insurance policies. Humana has not offered new individual ACA health insurance since January 2018 but will continue to honor its existing ACA policies. Humana is now focused on serving the Medicare market, with either a Medicare Advantage or a supplemental plan (or both) available in every state.

Largest major medical insurance provider by state

Individual health insurance policies can be purchased through the health insurance marketplace if you currently do not receive health care through an employer or a federally funded program like Medicaid or Medicare. In 2021, 13.6 million people enrolled in plans through the health insurance marketplace.

Below is the biggest health insurance provider in each state by total market share.

Health insurance company rankings by revenue

Based on our analysis, UnitedHealthcare is the largest health insurance company by revenue, with total revenue topping $286 billion for 2021. This makes the insurer the largest company by membership, market share and revenue. Anthem is the second-largest health care company in all three categories.

Health insurance companies create revenue through premiums, policy volume, the services they sell and the number of businesses they operate in.

Rank

Company

Revenue

1 UnitedHealth Group $286 billion
2 Anthem $138 billion
3 Centene $126 billion
4 Kaiser Permanente $89 billion
5 Humana $83 billion
6 CVS Health $61 billion
7 HCSC $47 billion
8 Molina Healthcare $20 billion

Frequently asked questions

What are the top five largest health insurance companies?

The largest health insurance companies include UnitedHealth Group, Anthem, Centene, Humana and Health Care Service Corp. (HCSC). These five companies represent nearly 46% of the total market share in the health insurance industry. UnitedHealthcare is the largest health insurer by market share, membership and revenue, with total revenue of over $286 billion in 2021.

How should one compare health insurance companies?

Comparing health insurance companies is crucial when shopping for a health insurance policy. Outside of premiums, deductibles and the plan network, companies can have a variety of differences. For example, some health providers offer extra benefits if you become a policyholder, such as gym memberships or discounts on health programs. These should not be the No. 1 reason you choose a company but are important to consider in the shopping process.

How should one determine the largest health insurance companies?

When determining what the biggest health insurance companies are, there are a variety of variables to analyze. Market share, for example, analyzes the portion of the industry that the company controls and therefore shows the company's reach among policyholders. Furthermore, market share is closely related to total membership, which shows the number of individuals that the company currently covers with health insurance. Finally, you can analyze revenue, which is a measure of how much money that company brings in annually.

Methodology

Market share data for 2021 was pulled using the S&P Capital IQ tool. Revenue figures for 2021 were found using the same analysis as well as by reviewing quarterly 10-Q and annual 10-K reports filed by the individual health insurance companies.