House Budget Committee Chairman Paul Ryan, R-Wis., is testing support for his idea to replace Medicare with a fixed payment to buy a private medical plan from a menu of coverage options.

Party leaders will determine if the so-called voucher plan will be part of the budget Republicans put forward in the spring.

"No decisions have been made on the details of our House GOP budget." Michael Steel, a spokesman for Speaker John Boehner, R-Ohio, said Thursday. "There are a lot of ideas out there, and we're going to listen to our members and the American people."

Medicare was one of the most highly charged issues during last year's congressional elections, which put the House back in GOP control. Republicans slammed Democrats for cutting Medicare by about 6 percent over 10 years to finance President Barack Obama's health overhaul.