Jason Furman, Kerry's 34-year-old director of economic policy, estimates that it would cut premiums for a typical worker's family by $1,000 a year.
Mr. Courter says he would use the free market to cut premiums through competition.
With that flexibility, Congress could cut premiums and control surpluses without long-term risk.
This can cut premiums by up to a third.
Such purchasing cooperatives can put downward pressure on insurers to cut premiums and improve the care of patients.
Private plans would have no incentive to cut premiums below the amount of the voucher.
American Mayflower is among several companies that have cut premiums by tightening health standards.
Mr. Kerry has promised to provide coverage for 27 million uninsured Americans and to cut premiums by 10 percent over all, among other things.
At the other is $250,000 in true no-fault protection, which would cut premiums by 20 to 25 percent.
When investment income is high, insurers can afford to cut premiums.