Patients with insurance, including Medicaid, are to pay their prescription program's lowest co-payment, which in many cases may be lower than the $10 fee.

Regular office visits have co-payments as low as US $5 per visit.

Officials also hope to offer additional benefits, like lower co-payments, to elderly people in the new system, making the change more attractive.

"We were induced to support this legislation after being told that the extra money would be used for extra benefits or lower co-payments."

Nissan has begun steering employees toward generic drugs by setting lower co-payments for them and higher co-payments for costlier medicines still under patent.

Because management for medical necessity allows for lower co-payments, people are able to get treatment who could never afford the traditional indemnity plan's 50 percent co-payment.

Some plans also charge lower co-payments if drugs are ordered by mail in 90-day supplies.

The plans use the revenue windfall to draw the elderly away from the Government plan by offering them additional benefits, like drug coverage and low co-payments.

Democrats say card sponsors should be allowed to set lower co-payments for people with lower incomes.

Instead, Express Scripts has devised a plan that will offer patients taking generic simvastatin a much lower co-payment on their prescriptions.