Quick answer
The best health insurance company is the one with the right doctors, drugs and price where you live, and that changes from state to state. For 2026, the insurers selling marketplace plans in the most states are UnitedHealthcare (30 states), Centene’s Ambetter (29), Oscar (20), Elevance Health’s Anthem plans (18), Molina (14), Cigna (11) and Kaiser Permanente (10), plus local Blue Cross Blue Shield companies. Cigna is leaving the marketplace in all 11 of its states for 2027, so check what’s sold in your area during open enrollment. For quality, check the star ratings on HealthCare.gov and NCQA’s health plan ratings.
Key takeaways
- No insurer is the best everywhere. Networks, drug lists and prices are set state by state, even county by county.
- Aetna left the ACA marketplace after 2025, and the average state now has 9 marketplace insurers, down from 9.6.
- Nonprofit and regional plans often score highest on quality. NCQA’s 2026 five-star plans include UPMC Health Plan, Blue Cross Blue Shield of Massachusetts, Harvard Pilgrim and several Kaiser Permanente plans.
- Compare networks, drug lists, deductibles and out-of-pocket limits, not just premiums.
- Every ACA plan covers the same essential benefits and pre-existing conditions, whichever company sells it.
On this page
Major health insurers at a glance
| Insurer | Marketplace states, 2026 | Good to know |
|---|---|---|
| UnitedHealthcare | 30 | The largest U.S. health insurer, and the biggest in Medicare Advantage |
| Centene (Ambetter) | 29 | Sells marketplace plans under the Ambetter name and is a major Medicaid insurer |
| Oscar Health | 20 | Focuses on individual plans, with app-based tools and virtual care |
| Elevance Health (Anthem) | 18 | Runs Blue Cross Blue Shield plans in many states, often under the Anthem name |
| Molina Healthcare | 14 | Mostly Medicaid and marketplace plans aimed at lower-income households |
| Cigna | 11 | Leaving the marketplace in all 11 of its states for 2027; still a large employer insurer |
| Kaiser Permanente | 10 | Insurer and care system in one; you use Kaiser doctors and hospitals |
| Local Blue Cross Blue Shield companies | Most states | Independent companies that often have large local networks |
A few other names you may know: Humana focuses on Medicare and left the individual market years ago. Aetna still sells employer and Medicare coverage but stopped selling marketplace plans after 2025. Regional insurers such as Highmark in Pennsylvania, Delaware, West Virginia and western New York, EmblemHealth in New York, and Utah-based Select Health can be strong choices where they operate.
How to find the best company for you
- Check the network. Make sure your doctors and nearest hospital are included. HMO and EPO plans generally won’t pay for non-emergency care outside the network.
- Check the drug list. Look up each medication you take and its tier.
- Compare the total cost. Add a year of premiums to the deductible and out-of-pocket maximum. See how you meet your deductible, whether copays count toward it, and whether a high or low deductible is better.
- Look at quality ratings. HealthCare.gov shows a 1-to-5-star quality rating for many plans, and NCQA rates plans on care quality and member experience.
- Look at complaints and service. Your state insurance department tracks complaints against insurers.
- Think about extras. Adult dental and vision care usually aren’t included in medical plans; see does Obamacare cover dental, does Obamacare cover vision and does health insurance cover eye exams.
For a full checklist, see comparing health insurance to find the best-fit plan.
Where to buy
You can buy ACA plans on HealthCare.gov or your state’s marketplace, or directly from an insurer. Premium tax credits are only available through the marketplace, so start there if you might qualify. Families with lower incomes should also check Medicaid and CHIP, and parents can find more in health insurance for children.
Be careful with products that aren’t ACA insurance. Short-term plans can be cheap but can exclude pre-existing conditions and skip essential benefits.
Insurer guides: Ambetter, Blue Cross Blue Shield, Cigna’s 2027 exit, Kaiser Permanente, Molina, Oscar and UnitedHealthcare.
See which insurers sell plans where you live: compare quotes by ZIP code.
Frequently asked questions
Which health insurance company has the most doctors?
It depends on your area. Blue Cross Blue Shield companies often have the largest local networks, but compare the specific plan, since one insurer can sell plans with very different networks.
Is a bigger company better?
Not necessarily. Some of the highest-rated plans are regional nonprofits. A national insurer may have a narrow network in your area.
Why did my insurer leave the marketplace?
Insurers enter and exit markets every year. If yours leaves, you’ll be moved to a similar plan or can pick a new one during open enrollment. See what to do if your insurance company leaves the Marketplace.
Are the best companies the most expensive?
Not always. Price depends on the network, the plan level and your county. Compare several plans side by side.
Sources
- KFF: How has insurer participation in the ACA marketplaces changed in 2026?
- KFF: Tracking insurer participation changes in the ACA marketplaces in 2027
- NCQA: 2025 health plan ratings, highest-rated plans by state
- Fierce Healthcare: NCQA’s 2026 ratings and five-star plans
- HealthCare.gov: Health insurance plan and network types
This article is general information, not an endorsement of any insurer. SelfHealthInsurance.com may be paid by partners when you click an offer. Plans and ratings change every year, so compare current options on HealthCare.gov or with a licensed agent. Last reviewed September 2026.