Comparing insurers, and why the brand matters least

Reviewed September 4, 2026 · Written by the HealthPlanIndex editorial team

The question people ask is "which insurer is best". It has no answer, because insurers do not compete nationally on quality — they compete county by county on which doctors they signed, which drugs they cover, and what they charge. The same company can be the obvious choice in one county and unavailable in the next.

How many insurers you get to choose between

This is the first thing worth knowing, and it is entirely local.

Across 1,817 counties with data. Source: CMS Marketplace Open Enrollment Public Use Files and US Census Small Area Health Insurance Estimates, 2026 release.

If you are in a one-insurer county, comparison shopping is not really available to you and the benchmark plan that sets your subsidy is whatever that insurer charged. If you are somewhere with eight, the benchmark is the product of real competition. Check which you are in before you start.

What actually distinguishes one insurer from another

Not the brand. Four things, in roughly this order:

1. The network. Which doctors and hospitals will take the plan. This is the single most consequential difference and the one people check last. How networks differ.
2. The formulary. Which prescription drugs are covered, in which tier, and what you pay for each. If you take something regularly, look this up by drug name before anything else.
3. How they handle prior authorization. Two plans with identical paperwork benefits can behave very differently when you need a procedure approved.
4. Price, which is where most people start and which matters least if the first three are wrong.

What the star ratings do and do not tell you

Marketplace plans carry a quality rating out of five, based on member experience, medical care and plan administration. It is a real signal and a coarse one: it is calculated at the level of the insurer's product in a state, not for the specific plan you are looking at, and a plan can be new enough to carry no rating at all. Treat it as a tiebreaker after network and formulary, not as the deciding factor.

Reference pages

• HMO, PPO, EPO and POS — what the letters mean for whether your doctor is covered.
• What Blue Cross Blue Shield actually is — it is not one company, which explains a lot of the confusion.