California's biggest health insurer is telling Congress that the soaring costs of medical care are to blame for rate increases of up to 39 percent it wants to impose in the state.

WellPoint President Angela Braly says the company realizes the increases can be tough for its customers. But in prepared testimony Wednesday, she's telling members of a House subcommittee that the higher rates are fair.

She says the increases are caused by growing costs for hospitalization and pharmaceuticals and by younger, healthier people dropping coverage in the tight economy.

WellPoint owns Anthem Blue Cross, whose rate increases for policyholders who buy their own insurance are being used by Democrats to show the need for health care overhaul.