About 1.9 million elderly and disabled people signed up for the new Medicare drug benefit over the past month, meaning 7.2 million have taken steps to enroll since the program began Jan. 1. The number should keep rising, the program's chief says.

An additional 20 million people have been enrolled automatically because they participate in other government programs, such as Medicaid, or because they have drug coverage through their former employer. Those employers are getting a tax subsidy to continue providing the coverage.

About 43 million people are eligible for the benefit.

"Since January, we've seen a steady, increasing rate of enrollment, and we expect to continue seeing that until May 15," Mark McClellan, administrator for the Centers for Medicare and Medicaid Services, said Thursday.

That is the deadline for enrolling. People who sign up later probably will have to pay higher premiums; many members of Congress have proposed extending the deadline past May 15.

Health and Human Services Secretary Mike Leavitt gave no indication that he agreed with that idea. Indeed, he said people should not wait until just before the deadline to enroll.

"We're reaching out to seniors to suggest there will be a surge at the end. Human nature tells you that," Leavitt said. "What that means is we'll likely see a lot of people trying to sign up at the same time. They can avoid that rush by signing up now."

The latest enrollment figures were released as polling showed that older people have mixed views about the program.

About 44 percent of those surveyed approve of the new benefit. About 41 percent disapprove and 15 percent are undecided, according to The Pew Research Center for the People and the Press. The margin of error was plus or minus 3 percentage points.

While political supporters of the benefit can take solace in that more people like the benefit than dislike it, the numbers represent a dwindling of support since December.

It would appear that many of the people who were undecided before the benefit kicked in now have a negative view of the program. In the December survey, 45 percent approved, 34 percent disapproved and 21 percent were undecided.

Groups urging an overhaul of the program said Thursday that thousands of elderly and disabled people are continuing to call hot lines to complain. The organizations, part of a group called the Americans United Coalition, said the public will support politicians who promise major changes to the program.

Defending the program as it is now "looks to be a losing political proposition in 2006," Democratic pollster Guy Molyneux said.

Young people are most supportive of the program, according to the Pew Research Center's survey. Among those age 18 to 29, about 64 percent approve and 22 percent disapprove.

The least supportive are people 50 to 65; some 40 percent approved and 44 percent disapproved.

McClellan said polling from other groups also shows that a majority of older people who do sign up are glad they did.

The elderly and disabled are eligible to enroll in a private drug plan or in a managed care plan, called Medicare Advantage, that will cover a portion of their drug costs. The government has estimated that the average participant will save about $1,100; the amount of savings varies depending upon a beneficiary's drug needs, income and the type of plan that they choose.