WASHINGTON_Congressional investigators said Wednesday two-thirds of the U.S. health insurance industry used a faulty database that overcharged patients for seeing doctors outside their insurance network, costing Americans billions of dollars in inflated medical bills.

The flawed database _ known as Ingenix _ is owned by health insurer UnitedHealth, which agreed in January to pay $350 million to settle allegations that it deliberately kept rates low to underpay doctors, driving up expenses for patients.

An investigation by Sen. John Rockefeller, D-W.Va., shows that nearly 20 regional and national insurers also used Ingenix data. An ongoing probe by New York Attorney General Andrew Cuomo previously focused on the use of Ingenix data by only a handful of top insurers, including Aetna, Wellpoint and Cigna. About a dozen insurers, including UnitedHealth, have already reached settlements with Cuomo.

Tuesday's report arrives as President Obama and Democrats in Congress step up calls for a public health care option, "to keep health insurance companies honest." The idea is vigorously opposed by Republicans and the insurance industry, who say a public plan would drive private companies out of the marketplace.


More than 100 million Americans have plans that allows them to see doctors who are not part of their insurance network. For more than a decade, insurers submitted data to Ingenix to determine the typical cost for care received outside their networks.

But congressional investigators say companies would deliberately skew data to underestimate the costs of medical services, leaving patients to pay more in out-of-pocket expenses.

In one case, Aetna eliminated the highest 20 percent of medical charges before sending the data to Ingenix, according to the report. Once the data was handed over to Ingenix, officials there "scrubbed" the numbers again to further curb charges.

"The result of this practice is that American consumers have paid billions of dollars for health care services that their insurance companies should have paid," states the report from the Senate Commerce Committee's investigative staff.

UnitedHealth has admitted no wrongdoing in its handling of Ingenix, though it agreed to close the database and help fund a new one operated by a nonprofit.

Rockefeller and other lawmakers are pushing for additional changes in the insurance marketplace. A bill from the West Virginia Senator, who chairs the Commerce Committee, would compel companies to disclose more about how they determine out-of-network rates.