Best Health Insurance Companies Compared
HSChange Editorial Team
Health Policy Research Team, Consumer Health Guidance
Reviewed by Dr. Sarah Mitchell, MD, MPH, Board-Certified Internal Medicine
Last updated: April 4, 2026
There's no single "best" health insurance company. The right choice depends on where you live, what doctors you want to see, what medications you take, and how much you can spend. But some insurers consistently score higher on quality, customer satisfaction, and network breadth. Here's how the biggest players compare.
The Largest U.S. Health Insurers
By enrollment, the five biggest are UnitedHealthcare (about 50 million members), Elevance Health/Anthem (about 47 million), CVS/Aetna (about 23 million), Cigna (about 18 million), and Humana (about 17 million). Kaiser Permanente, while smaller nationally, serves over 12.5 million members and consistently earns the highest quality ratings in the regions it operates.
Quality and Satisfaction Ratings
NCQA (National Committee for Quality Assurance) rates health plans on a 0 to 5 scale. Kaiser Permanente and several Blue Cross Blue Shield affiliates consistently score highest. J.D. Power's 2025 Commercial Member Health Plan Study also ranks Kaiser at the top in member satisfaction in most regions.
Keep in mind that a national insurer's quality can vary by state and plan type. UnitedHealthcare might score well in Texas but mediocre in New York. Always check ratings for the specific plan and region you're considering.
The Medical Loss Ratio Rule
The ACA requires all marketplace insurers to spend at least 80% of premiums on medical care and quality improvement (85% for large group plans). This Medical Loss Ratio rule means insurers can't pocket more than 20% for overhead and profit. If they do, they owe you a rebate. This applies to every insurer on the marketplace equally, so you're protected regardless of which company you pick.
Network Size Matters More Than Brand
The most important thing about any insurer is whether your doctors are in their network and whether your medications are on their formulary. A plan from a top-rated insurer is worthless to you if your oncologist or cardiologist isn't covered. Check provider directories before you compare anything else.
Plan availability also varies dramatically by location. Some rural counties have only one or two insurers on the marketplace. Urban areas might have five or more. Blue Cross Blue Shield affiliates have the broadest geographic reach, operating in all 50 states.
How to Choose
Start with your doctors and medications. Narrow to plans that cover both. Then compare total annual cost (premiums plus expected out-of-pocket spending), not just the monthly premium. Check the insurer's NCQA rating for your state. If you're buying through the marketplace, use Healthcare.gov to see all available plans side by side with estimated total costs based on your expected usage.
If the comparison feels overwhelming, a licensed health insurance broker can walk you through it at no cost to you.