Top 5 largest health insurance companies 2024

Each of the leading health insurance companies boasts millions of customers. There are various avenues through which you can enroll in a health insurance policy from one of these major companies. For instance, your employer’s benefit plan may provide health insurance, or you can purchase a private insurance plan through the Affordable Care Act (ACA) marketplace, also known as “Obamacare.”

1. UnitedHealth Group

UnitedHealthcare policies are available for purchase directly in all 50 states. Individual and family plans on the health insurance exchanges can be obtained in approximately half of the states. UnitedHealthcare is headquartered in Minnetonka, MN.

UnitedHealthcare maintains a network of over 1.3 million doctors and healthcare professionals, along with more than 6,500 hospitals. This extensive network ensures that if you have UnitedHealthcare, you will have numerous options for receiving medical care.

2. Anthem

Anthem currently offers plans in 14 states, including California, Colorado, Connecticut, Georgia, Indiana, Kentucky, Maine, Missouri, Nevada, New Hampshire, New York, Ohio, Virginia, and Wisconsin.

As part of the Blue Cross Blue Shield Association, Anthem contributes to nationwide coverage through the BlueCard program. The Blue Cross Blue Shield provider network, covering about 90% of doctors and hospitals, is the largest in the country.

3. Kaiser Permanente

Kaiser Permanente operates exclusively in eight states and the District of Columbia. Despite its limited geographic scope, the company is highly popular in the regions it serves. Kaiser Permanente focuses on low-cost HMO plans, requiring the use of Kaiser’s medical centers for coverage.

4. Ambetter

Ambetter, a key subsidiary of Centene, specializes in selling individual health insurance plans. Notably, Ambetter does not offer Medicare Advantage or Medicare Part D plans; these are primarily sold by Wellcare, another Centene subsidiary.

Centene, established in 1984, started as a provider of Medicaid plans and has grown to become the largest provider of managed care Medicaid plans in the country.

5. Humana

Humana concentrates on employer health insurance plans, dental and vision insurance, and Medicare plans, including Medicare Advantage, supplemental, and prescription plans. Since January 2018, Humana has not introduced new individual ACA health insurance plans.

Largest major medical insurance provider by state

Blue Cross Blue Shield, including affiliates like Anthem, is the largest health insurance company in most states based on membership. You can purchase individual health insurance policies through the health insurance marketplace if you don’t currently have coverage through an employer or federally funded programs like Medicaid or Medicare. For the 2023 plan year, 16.3 million people enrolled in plans through the health insurance marketplace.

Health insurance company rankings by enrollment

Kaiser Permanente holds the title of the largest health insurance company by enrollment, boasting nearly 9 million members with an individual or group health insurance plan. Although Kaiser’s plans are available in only eight states and Washington, D.C., its high enrollment in those areas is noteworthy. However, in terms of revenue, Kaiser Permanente is not the top-ranking company, as it focuses on providing affordable health insurance plans, including low-cost HMO plans. Anthem follows as the second-largest in terms of membership, with UnitedHealthcare coming in third.