President Bush stepped Monday into the controversy over the first part of the new Medicare law that has gone into effect, acknowledging that "we've got some problems" with the drug discount cards that became available two weeks ago.

With fewer than expected older Americans signing up for the cards and Democrats working to fan opposition to the law, Bush said that some Medicare patients are shying away because they consider it too complicated to get a card. Still, he delivered a strong defense -- and accompanied a 74-year-old woman to a local pharmacy where she used her new card to save $17 on her blood-pressure medicine.

"This discount card is going to save our seniors a lot of money," Bush said.

The president's remarks in this northeastern suburb of Kansas City marked the first time he has devoted a trip to promoting the discount cards, a temporary approach intended to help people on Medicare buy medicine for less. The cards do not provide government subsidies, but they allow people in the health insurance program for the elderly and disabled to buy one of 73 privately administered cards, approved by the government, that offer lower prices at drugstores or mail-order pharmacies.

Bush and other Republicans are eager to tout the cards as evidence they are helping older Americans, even though it will be two years until the start of the drug benefit that is the centerpiece of the Medicare law passed in November by a bitterly divided Congress. Democrats are working just as hard to discredit the cards and to try to blunt the GOP's ability to take credit for updating Medicare. Hours before Bush spoke, John F. Kerry's presidential campaign issued a stinging critique of the program, saying it often will leave older Americans paying higher prices for prescriptions than they already can obtain through other kinds of pharmaceutical discounts. Kerry renewed his call for two strategies to try to lower drug prices that the new law prohibits: allowing the government to negotiate discounts directly with pharmaceutical companies and making it legal for people of all ages to import U.S.-manufactured drugs from Canada and other countries where they are sold at lower prices.

Bush reiterated that he was willing to expand an enormous federal entitlement only by relying on private health plans and companies that manage pharmacy benefits. "One of the things I believe is that markets have got a fantastic way of rewarding people with better quality and better price," he said.

Monday's visit was classified by the White House as an official presidential trip, not a campaign event, so it was paid for with public funds. But, like most of the president's travels across the country in this election year, the destination had political overtones. Bush carried Missouri by 3 percentage points in 2000, and recent polls suggest that he and Kerry are closely matched here.

Since Bush signed the Medicare law six months ago, a variety of surveys have found widespread public dissatisfaction with it, including the discount cards. A spokesman for AARP, the nation's largest organization of older Americans, said enrollment in the card that group is sponsoring is running lower than expected. As of late last week, nearly 49,000 people had contacted AARP to request information about the card, but just 5,900 had signed up. "People are having a tough time" understanding the program, said the spokesman, Steve Hahn. "They are a bit confused, and they are getting overwhelmed with information."

Bush's senior health advisers have predicted that 7 million people will sign up for a card by the end of the year. So far, 3.3 million Medicare patients are enrolled, but fewer than one-third of them have deliberately signed up; the rest were enrolled automatically by private health plans to which they belong, according to Mark B. McClellan, administrator of the Centers for Medicare and Medicaid Services, who accompanied the president here.

McClellan and Bush emphasized that the government has set up a round-the-clock toll-free phone number to help Medicare patients determine which cards would be best for them, given the prescriptions they take.

On Monday, the president, like other Republicans, touted as a major selling point of the program the $600 subsidy the cards offer to people with low incomes. Sharing the stage in the Liberty Community Center were two women in their seventies who qualified for that help -- and gave testimonials to reinforce the administration's case.

"I can tell you the drug card is working," said Gladys Cole, 73, of Kansas City, who lives on her Social Security income. She used her card for the first time last week and was charged $22 by the pharmacist for two prescriptions that usually cost her about $120. "He told me what the savings was. I just about dropped my false teeth."

President Bush helps a Missouri woman with a new discount prescription card.