Top 10 Health Insurance Companies in USA 2026

The US health insurance market is dominated by a few giants.

A handful of these companies cover most of the country, providing employer coverage, Medicare Advantage and Medicaid plans and selling policies on the Affordable Care Act exchanges. According to the Centers for Medicare & Medicaid Services (CMS), 23.1 million Americans selected a plan or were automatically re-enrolled in one for 2026 through the ACA exchanges. Many are publicly traded, but others, such as Kaiser Permanente and several Blue Cross Blue Shield companies, are nonprofits or owned by their customers.

We ranked these companies by total medical enrollment in 2025, using Mark Farrah Associates data as published by the Peterson-KFF Health System Tracker and reported by Becker’s Payer Issues in December 2025. That count includes individual, group, Medicaid and Medicare Advantage enrollment, about 320 million in all. Because each insurer counts members its own way, company-reported figures often run higher or lower, so we have included each company’s latest 2026 numbers in its profile.

Also Read: Top 10 Healthcare Companies in USA 2026

In this article we cover the top 10 health insurance companies in USA for 2026, what each one specializes in and who it suits.

Why the Largest Health Insurance Companies in USA Matter in 2026

Your health insurance company affects which providers you can see, what you pay for coverage and how smoothly your claims get paid. Here is why these companies matter so much in 2026.

Marketplace Coverage Is Still Near Record Levels

CMS called 2026 exchange enrollment a “near record high,” with 23.1 million sign-ups. Consumers also shifted toward lower-cost plans: Bronze rose by about 10 percentage points while Silver dropped by nearly 14, leaving a 2026 mix of 40% Bronze, 43% Silver and 17% Gold.

A Few Insurers Cover Most Americans

UnitedHealth Group and Elevance Health alone made up about 81 million of the roughly 320 million enrollments in 2025. These companies are so big that when they change networks or pricing, millions of members feel it.

Medical Costs Are Squeezing Even the Biggest Plans

With costs rising, even the biggest insurers struggled in 2025. Health Care Service Corporation reported a net loss of more than $1.9 billion, and Blue Cross Blue Shield of Michigan reported a $246 million loss amid higher health care and drug costs.

Government Programs Drive Growth

Most of these companies offer Medicare Advantage and Medicaid plans. On October 8, 2026, CMS released the 2027 Medicare Advantage Star Ratings, which affect the bonus payments plans can use for extra member benefits.

Top 10 Health Insurance Companies in USA at a Glance

Top 10 Health Insurance Companies in USA (2026)

Here are the top 10 health insurance companies in USA, ranked by 2025 medical enrollment.

1. UnitedHealth Group (UnitedHealthcare)

UnitedHealth Group is the largest health insurance company in the country by enrollment, with 44.8 million members in 2025 according to Mark Farrah. The Minnesota-based group has two divisions: UnitedHealthcare, which sells employer, individual, Medicare and Medicaid plans, and Optum, which provides care delivery, pharmacy benefits and data services.

As of September 30, 2026, UnitedHealthcare served 48.3 million people, including 29.76 million in commercial plans, 7.61 million in Medicare Advantage and 6.70 million in Medicaid. Group revenue for the third quarter of 2026 was $112.7 billion, slightly down from $113.2 billion a year earlier. Chairman and CEO Stephen Hemsley raised the 2026 outlook to adjusted earnings of at least $20.50 per share.

Key Health Insurance Solutions
✔ Employer-sponsored and individual health plans
✔ Medicare Advantage plans
✔ Medicaid managed care
✔ Optum Rx pharmacy benefits

Best for: Employers and families who want a national network and plans in nearly every market.

2. Elevance Health (Anthem)

Elevance Health traces its roots to Indianapolis in 1946 and still operates out of the city today. It was known as Anthem until June 2022. Elevance is the Blue Cross Blue Shield licensee in 14 states and sells plans under the Anthem name. Mark Farrah counted 36.1 million members in 2025, second only to UnitedHealth.

Total medical membership was 44.9 million as of September 30, 2026, down 1.1% from a year earlier due to lower Medicaid and Medicare enrollment. Operating revenue rose 0.7% to $50.4 billion in the third quarter of 2026, and CEO Gail Boudreaux raised 2026 guidance to adjusted earnings of at least $29 per share. Elevance also provides pharmacy and care services through its Carelon unit, including CarelonRx.

Key Health Insurance Solutions
✔ Anthem Blue Cross Blue Shield employer and individual plans
✔ Medicare and Medicaid plans
✔ CarelonRx pharmacy services
✔ Carelon care management

Best for: People and employers in Anthem’s Blue Cross Blue Shield states who want broad local networks.

3. CVS Health (Aetna)

Aetna was founded in Hartford, Connecticut, in 1853. It became part of CVS Health when CVS completed its $69 billion acquisition on November 28, 2018. Aetna now sits in CVS Health’s Health Care Benefits segment, under the same roof as the CVS Caremark pharmacy benefit manager and CVS Pharmacy. Mark Farrah put its 2025 enrollment at 24.9 million.

As of June 30, 2026, CVS reported 26.0 million medical members: 18.3 million commercial, 4.2 million Medicare Advantage, 1.2 million Medicare Supplement and 2.3 million Medicaid. Health Care Benefits revenue rose 3.5% to $37.5 billion in the second quarter. Chairman and CEO David Joyner raised 2026 guidance to adjusted earnings of $7.90-$8.10 per share.

Key Health Insurance Solutions
✔ Aetna employer plans, including self-funded options
✔ Medicare Advantage and Medicare Supplement
✔ Aetna Better Health Medicaid plans
✔ Links to CVS Caremark pharmacy benefits

Best for: Employers and individuals who want coverage tied to a national pharmacy network.

4. Centene (Ambetter and Wellcare)

Centene was founded in 1984 and is headquartered in St. Louis, Missouri. It calls itself the nation’s largest Medicaid managed care company, and it bought Wellcare in January 2020. Centene sells its Marketplace plans under the Ambetter brand, and Wellcare is now its Medicare business. Mark Farrah counted 19.0 million members in 2025.

As of September 30, 2026, Centene reported 25.7 million at-risk members, including 11.9 million in Medicaid, 3.4 million in Marketplace plans and 954,400 in Medicare. Third-quarter 2026 revenue was $50.6 billion, up from $49.7 billion a year earlier. CEO Sarah London raised 2026 guidance to adjusted earnings of more than $5.20 per share and expects revenue of $196.5-$200.5 billion.

Key Health Insurance Solutions
✔ Medicaid managed care in many states
✔ Ambetter Health Marketplace plans
✔ Wellcare Medicare Advantage and prescription drug plans

Best for: Medicaid members and budget-focused Marketplace buyers.

5. Health Care Service Corporation (HCSC)

Health Care Service Corporation began offering health insurance in 1936 and is headquartered in Chicago. It provides Blue Cross and Blue Shield coverage in Illinois, Montana, New Mexico, Oklahoma and Texas, and describes itself as the largest customer-owned health insurer in the United States. Mark Farrah counted 18.7 million members in 2025.

HCSC grew significantly after completing its purchase of Cigna’s Medicare and CareAllies businesses on March 19, 2025. Revenue reached $66.8 billion in 2025, up from $62.8 billion, and the company says it serves about 27 million people. Despite this growth, HCSC reported a net loss of more than $1.9 billion for 2025. Maurice Smith is chairman, president and CEO.

Key Health Insurance Solutions
✔ Blue Cross and Blue Shield employer and individual plans
✔ Medicare Advantage, supplement and Part D plans
✔ CareAllies care management services

Best for: People and employers in Illinois, Texas, Oklahoma, New Mexico and Montana who want a Blue plan.

6. The Cigna Group (Cigna Healthcare)

The Cigna Group is based in Bloomfield, Connecticut. Cigna Healthcare sells medical plans mainly to employers, while Evernorth Health Services, home to Express Scripts, brings in most of the company’s revenue. Cigna sold its Medicare business to HCSC in March 2025. Mark Farrah counted 16.2 million members in 2025.

As of June 30, 2026, Cigna had 18.4 million medical customers, a 2% increase from the end of 2025. Cigna Healthcare’s adjusted revenue rose 9% to $11.7 billion in the second quarter of 2026, and total revenue rose 7% to $71.7 billion. President and CEO Brian Evanko raised the 2026 outlook to adjusted earnings of at least $30.45 per share.

Key Health Insurance Solutions
✔ Employer medical plans, including self-funded options
✔ Dental and behavioral health coverage
✔ Express Scripts pharmacy benefits

Best for: Employers that want medical and pharmacy benefits from one company.

7. Kaiser Permanente

Kaiser Permanente was founded in 1945 and is based in Oakland, California. It not only provides insurance but also delivers care, with 55 hospitals and 847 medical offices at the end of 2025. Kaiser Permanente serves California, Colorado, Georgia, Hawaii, Maryland, Oregon, Virginia, Washington and the District of Columbia. Mark Farrah counted 12.3 million members in 2025.

Kaiser Permanente reported operating revenue of $127.7 billion in 2025, up from $115.8 billion in 2024. In the second quarter of 2026, revenue grew to $35.6 billion and membership reached nearly 13.4 million. Kaiser Permanente also ranked first on Insure.com’s 2026 list of the best health insurers, with the highest NCQA score among the companies reviewed. Greg A. Adams is chair and CEO.

Key Health Insurance Solutions
✔ HMO plans with in-house hospitals and doctors
✔ Employer and individual coverage
✔ Medicare Advantage and Medicaid plans

Best for: People in Kaiser’s regions who want insurance and care under one roof.

8. Humana

Humana was founded in 1961 and is headquartered in Louisville, Kentucky. It exited the employer group commercial market after announcing the decision in February 2023. Humana now focuses on Medicare Advantage plans and its CenterWell business, which provides senior primary care, home health and pharmacy services. KFF ranks Humana as the second-largest Medicare Advantage parent company in 2026. Mark Farrah counted 7.5 million members in 2025.

Humana reported second-quarter 2026 revenue of $40.9 billion, up from $32.4 billion a year earlier, and expects individual Medicare Advantage membership to grow about 25% in 2026. President and CEO Jim Rechtin has affirmed guidance of adjusted earnings of at least $9.00 per share. Humana also placed second on Insure.com’s 2026 best health insurers list, with the highest customer survey score.

Key Health Insurance Solutions
✔ Medicare Advantage plans
✔ Medicare prescription drug plans
✔ CenterWell Senior Primary Care
✔ Medicaid plans in select states

Best for: Seniors who want a Medicare Advantage plan linked to primary care.

9. GuideWell (Florida Blue)

GuideWell is a mutual holding company based in Jacksonville and the parent of Florida Blue, whose roots go back to 1944. Florida Blue says it is the largest and oldest health insurer in Florida and the only one serving all 67 Florida counties. Mark Farrah counted 6.1 million members in 2025.

GuideWell ranked No. 140 on the 2026 Fortune 500 with $32.9 billion in 2025 revenue. Florida Blue has about 6 million members and a network of about 1.7 million providers. Brian Pieninck became president and CEO of GuideWell on October 1, 2025, after serving as CEO of CareFirst BlueCross BlueShield.

Key Health Insurance Solutions
✔ Individual and family plans across Florida
✔ Employer group coverage
✔ Medicare Advantage and supplement plans

Best for: Floridians who want the widest in-state network.

10. Blue Cross Blue Shield of Michigan

Blue Cross Blue Shield of Michigan describes itself as the largest provider of health insurance in Michigan, and it has served the state for more than 80 years. It is a nonprofit, independent licensee of the Blue Cross Blue Shield Association, and its family of companies includes Blue Care Network and Blue Cross Complete of Michigan. Mark Farrah counted 4.9 million members in 2025.

Blue Cross Blue Shield of Michigan and its affiliates had about 5.1 million members at the end of 2025. Consolidated revenue rose to $43.3 billion from $40.6 billion, but the company reported a $246 million loss. President and CEO Tricia Keith is pushing a $600 million, three-year cost-cutting plan, and $420 million in savings has been achieved so far.

Key Health Insurance Solutions
✔ Employer group PPO and HMO plans
✔ Blue Care Network HMO coverage
✔ Medicare Advantage plans
✔ Blue Cross Complete Medicaid plan

Best for: Michigan employers and residents who want a large statewide network.

How to Choose the Right Health Insurance Partner in USA

Knowing the size of each insurer is helpful, but what matters most is whether a plan fits where you live, how you use care and what you can afford. Here are some things to consider.

Confirm Your Doctors Are in Network

Make sure the doctors and hospitals you want to use are in network. A low monthly premium doesn’t matter if your doctors aren’t covered. Search the insurer’s provider directory and call the office to confirm before you enroll.

Pick the Right Plan Type

HMO plans usually cost less but limit you to providers in their network, and you may need a referral from your doctor. PPO plans cost more but let you see out-of-network providers at a higher price. EPO plans fall in between.

Compare Total Costs, Not Just Premiums

Add up premiums, deductibles, copays and the out-of-pocket maximum to see what you will really pay. On the Marketplace, Bronze plans have lower monthly premiums but higher costs when you get care, while Gold plans have higher premiums but lower out-of-pocket costs.

Check Quality Ratings and Complaints

Look up NCQA health plan ratings and, if you are considering Medicare Advantage, the CMS Star Ratings on Medicare.gov. Your state’s insurance department and the NAIC complaint index show how often members file complaints against an insurer.

Look at the Insurer’s Financial Strength

Some of the larger health insurers reported losses in 2025. Ratings from AM Best or Moody’s, along with recent results, show whether a company is financially stable enough to pay claims and keep its plans in your area.

Frequently Asked Questions About Health Insurance Companies in USA

Which is the largest health insurance company in the USA?

UnitedHealth Group. Its UnitedHealthcare business had 44.8 million members in 2025 by Mark Farrah’s count, and it served 48.3 million people as of September 30, 2026.

Which health insurer is rated the best in 2026?

There is no single best insurer for everyone. In Insure.com’s 2026 ranking, which is based on a customer survey, NCQA ratings and NAIC complaint data, Kaiser Permanente came first and Humana second. The right insurer for you depends on your state, your doctors and your budget.

Is Blue Cross Blue Shield one company?

No. Blue Cross Blue Shield is a federation of independent companies licensed by the Blue Cross Blue Shield Association. Elevance Health, Health Care Service Corporation, Florida Blue and Blue Cross Blue Shield of Michigan are all separate Blue licensees on this list.

Why aren’t Molina Healthcare or Oscar Health on this list?

They have fewer members than the companies listed above. Molina Healthcare had about 4.9 million members as of September 30, 2026, and Oscar Health had about 2.96 million as of June 30, 2026, after adding nearly 1 million members in a year. Both are good options for people in Medicaid or buying on the Marketplace.

Conclusion

The top 10 health insurance companies in USA accounted for about 190 million enrollments in 2025. UnitedHealth Group and Elevance Health lead the pack by a wide margin, while CVS Health’s Aetna, Centene, Health Care Service Corporation and Cigna form a strong second tier. Kaiser Permanente, Humana, Florida Blue and Blue Cross Blue Shield of Michigan round out the list and show that a focused model, whether integrated care, Medicare or a single state, can still attract millions of members.

With changes to Medicaid, Medicare payment rates and the cost of medical care, these rankings will shift from year to year. Before you buy a plan, research its provider network, total costs and quality ratings, and check the insurer’s latest results.

Related Reading:

• Top 10 Biotech Companies in USA 2026
• Top 10 Pharmaceutical Companies in USA 2026
• Top 10 Health Insurance Companies in Dubai 2026