WASHINGTON -- Signup for Medicare's prescription drug coverage begins Tuesday, and over the weekend, President George W. Bush took to the airwaves to trumpet the program.

The president used his weekend radio chat to urge seniors to take advantage of the benefit.

Bush has spent much of the year touting the new coverage to elderly audiences. Medicare recipients can choose from among various competing private drug plans. Those who select by year's end will start getting help buying drugs in January.

Bush has also defended the benefit against Democrats who say the system's hopelessly complex and against conservative Republicans who complain it costs too much. The administration successfully beat back an attempt by GOP lawmakers to cut or delay implementation to help pay for Hurricane Katrina rebuilding.

Seniors may sign up from Nov. 15, 2005, to May 15, 2006. If they join by Dec. 31, 2005, their coverage will start Jan. 1, 2006.

If seniors don't sign up when they are first eligible or by May 15, 2006, they may pay a penalty.

The next opportunity to enroll is from Nov. 15, 2006, to Dec. 31, 2006.

Meanwhile, the program is generating a mixed review among the nation's seniors.

Last week, a Kaiser Family Foundation survey of 802 people age 65 or older found 37 percent of them have an unfavorable view of the program, 31 percent like it and 31 percent don't know enough about it to have an opinion.