More than 3 million Americans have signed up for Medicare drug discount cards (search), but confusion persists, a Senate panel was told Tuesday.

Medicare chief Mark McClellan and supportive lawmakers said problems were expectable in a program launched less than six months after the Medicare (search) law was enacted, but congestion on telephone lines and other problems were abating.

"Medicare beneficiaries ... can now get prices for their prescriptions that are significantly less than Americans generally pay," McClellan told the Senate Finance Committee a week after the cards took effect.

About 2.4 million of the 3 million-plus enrollees are members of health maintenance organizations who were enrolled automatically in their HMOs' card programs, McClellan said. Another 400,000 low-income Medicare recipients, who already receive help with their prescriptions, are in the process of being enrolled by state drug assistance programs, he said.

However, McClellan acknowledged that many people remain confused about the program and attributed some of the confusion to misinformation distributed by the law's critics.

Sen. Charles Grassley, (search) R-Iowa, the committee chairman, went even further. "The drug discount card program has been the target of a deliberate campaign to discredit it and confuse seniors about how it works," Grassley said.

The most extensive publicity effort, however, belongs to the Bush administration. It has spent about $50 million so far for television and other media advertising campaigns. The most widely seen critical advertisements was aired by AARP (search), the largest advocacy organization for older Americans, which backed the Medicare legislation last fall. AARP's ad highlights the law's complexity and suggests that AARP can make it understandable.

Several lawmakers and an array of seniors' advocates, including some supporters of the Medicare law, said the card program is complicated and time-consuming to explain. They pressed McClellan to expand automatic enrollment of low-income beneficiaries.

"It's taking a careful review to determine if the cards are a good thing," said Kris Gross, director of the Iowa Senior Health Insurance Program.

Sen. Kent Conrad (search), D-N.D., introduced legislation Tuesday to require the administration to reduce the number of cards available to three for each region of the country, require card sponsors to keep discounts at least as deep as they were when a client signed up and prohibit sponsors from dropping medicines.

"What I found is that people are confused. They're confused because there are so many cards," Conrad said.

Robert Hayes, president of the Medicare Rights Center in New York, used the example of a 75-year-old Oregon man who testified enthusiastically last month to a House committee that he was looking forward to cutting his $400-a-month drug bill to $250 with his Medicare drug card.

Hayes said Stan Baumhofer of Portland could have been getting all four prescriptions for $6 a month through low-income assistance programs offered by AstraZeneca, Bristol-Myers Squibb, Merck and Pfizer.

"You have to dig in deeply to see what is best for the individual," Hayes said.

In a telephone interview Tuesday, Baumhofer said he is happy with the discount card he's using, but the Medicare operator who helped him select a card had no information about manufacturer programs.

"I'm going to pick up a prescription right now that is one-third less," Baumhofer said. "Of course, free is better than anything."