The penalty will increase future premiums by 7 percent or more, for an expected surcharge of $2.50 a month next year.

He added that in addition to charging higher rates for insurance, companies can use other methods to increase premiums.

Any action to prevent those cuts would further increase Medicare spending and premiums, they said.

Or, they could ask the company to increase premiums.

Oxford said that it had already increased premiums by about 9 percent for many of its plans.

A high claims history, she said, can then increase premiums even if the carrier is regularly changed.

"If we have another long, hard winter then insurance companies will soon start to increase premiums."

Insurers then increase premiums for companies that provide health benefits, and they in turn shift some costs to employees.

"Their plan would increase premiums and other costs for senior citizens," he said.

Another would increase premiums for all beneficiaries except those with very low incomes.