Consumer Reports analyzed 984 private, Medicare, and Medicaid health insurance plans ranked by the national Committee for Quality Assurance, or NCQA, a nonprofit accreditation organization.
"The rankings take a number of factors into consideration, including customer satisfaction and how good a job the plan does on treatment and prevention," said Nancy Metcalf of Consumer Reports.
On the plus side, the quality of care has improved. But Consumer Reports says there are troubling trends as well.
"There are treatments and tests that have been shown not to be helpful, yet research shows many are still being overused," Metcalf said. "That's not only a waste of money, but you could end up getting treatments that are unnecessary, and sometimes even dangerous."
It turns out that the providers of the top 10 private plans are all nonprofits.
"That means they don't have to worry about turning a profit for investors, they only care about pleasing their customers," Metcalf said.
In the rankings, big name for-profit companies - United Healthcare, Aetna and Humana - had more private plans at the bottom than at the top.
When it comes to shopping for insurance, a new form will make the process much easier.
"For the first time, every plan will have a form that looks exactly the same, which will make it much easier to compare them side by side," Metcalf said.
The new form will allow people to have a much easier time comparing different policies.
In the Consumer Reports analysis, not all insurance plans were accredited and some were accredited by another organization. There was a fee involved for any accreditation.
Consumer Reports says getting accredited is an important step because it shows insurers are willing to report on their plans performance, and that has led to improved performance.