The largest health insurance companies that control nearly 75% of the market, ranked

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A general view outside the United Healthcare corporate headquarters on December 4, 2024 in Minnetonka, Minnesota.

Image: Stephen Maturen / Stringer (Getty Images)

Over the past few years the health insurance industry has experienced a series of major mergers and acquisitions, further consolidating power into the hands of a few dominant companies — leaving Americans with fewer options.

In 2018, CVS Health (CVS) acquired Aetna. That same year Cigna (CI) bought Express Scripts and in 2023, Kaiser Permanente merged with Geisinger.

As of 2023, just four health insurers control a staggering 50% of the market, while six companies account for 30% of all healthcare spending in the United States.

While these mergers have boosted profits for these companies, they also, in some cases, raised premiums for consumers.

Here is a ranking of the largest health insurance companies by market share: