For potentially thousands of lower-income Medicare recipients, the benefit of free drugs from pharmaceutical companies is suddenly becoming a burden.

If they decide to stay with the free drugs and not enroll in the new Medicare Part D drug program by May 15, they'll have to pay an increasingly large penalty to get in later should their medical needs or the pharmaceutical companies' programs change.

The Catch-22 situation is another example of how the new benefit, which promises help to people who previously lacked drug coverage, has created confusing or difficult decisions for beneficiaries already receiving some sort of pharmacy benefit.

As seniors have immersed themselves in the details of the Part D plan, a growing number have become frustrated by these nettlesome issues. A new nationwide poll released last week by the nonpartisan health policy group Kaiser Family Foundation found retirees were almost twice as likely to say they viewed the benefit unfavorably as favorably.

For years, thousands of patients with limited incomes have received free or reduced-cost drugs through assistance programs operated by drug companies. Eligibility criteria for these programs vary, but typically, free drugs are not provided to people who already have insurance coverage.

Medicare beneficiaries in these programs don't necessarily need the new Medicare prescription drug benefits that are being sold this winter, but their circumstances could change in ways, such as the need for a new drug, that would make a new Part D plan necessary. Moreover, pharmaceutical companies are under no legal obligation to provide the free or lower-cost drugs, and there are some concerns that the programs could conflict with Part D.

For the time being, there's not a final answer as to what consumers should do, said Tricia Neuman, a vice president and director of Medicare research with the Washington, D.C.-based Kaiser Family Foundation.

"Some of the companies are trying to set up alternate systems through charitable organizations" so they can help beneficiaries who enroll in Part D plans, said Ms. Neuman. "But until all that sorts itself out, [some patients'] best bet probably is to stick with what they have for now, but do research about Part D options ... and reassess the situation in April."

While it's unclear exactly how many Medicare beneficiaries are confronting this glitch, those affected stand alongside other groups of consumers who have experienced rough transitions this winter.

The most widely reported set of problems has involved Medicare beneficiaries who previously received drug coverage through state Medicaid programs and have struggled to obtain Part D benefits at the pharmacy. In the Pittsburgh area, many PACE recipients have complained that the transition is forcing them either to switch Medicare health plans or buy duplicate drug coverage to maintain their existing benefits.

"Each one is a little different, but they all share this 'I had this nice, stable situation' aspect, where people knew what they had, even if it was somewhat spotty help through pharmaceutical assistance programs," said Jack Hoadley, a health policy researcher at Georgetown University. "Now they have to disrupt that and at least make a decision, or in many cases make a shift. That's hard for people."

The dilemma involving pharmaceutical assistance programs first surfaced in November with a special advisory bulletin from the U.S. Department of Health and Human Services Office of Inspector General.

Assistance programs from drug companies could run afoul of federal anti-kickback statutes because they could steer people in Part D plans to the company's drugs, the bulletin said, even if less expensive, equally effective drugs are available.

The government fears the use of higher-priced drugs in these company plans could drive up future costs to Medicare, the bulletin said, endangering the breadth of the Part D program.

Last month, the Centers for Medicare and Medicaid Services issued a statement that reiterated the government's concerns while noting that drug companies can still provide free or reduced price drugs to financially needy Part D beneficiaries, so long as the assistance program is properly structured. One such structure would be for companies to make cash donations to independent charities that assist Medicare beneficiaries with drug expenses, the CMS said.

That solution gives pause to drug companies. The concern is that an independent charity could take a contribution from one company and use the money to buy drugs from a competitor.

As companies figure out what they will do, Medicare beneficiaries who receive medications through pharmaceutical assistance programs should first check to see if they qualify for limited-income subsidies that are available in the Part D program, said Ms. Neuman, the Kaiser Family Foundation official.

With subsidies, a Medicare beneficiary would not incur dramatically higher costs for the particular medicines being provided by the companies, Ms. Neuman said. Plus, the beneficiary would have comprehensive drug coverage.

"You never know when you're going to need a new drug," she said.

For beneficiaries with income or assets that make them ineligible for subsidies, the prudent thing to do is to wait before selecting a Part D plan, Ms. Neuman said. Not only might drug companies change their programs in the coming months, but also some politicians have talked about delaying the May 15 enrollment deadline or waiving penalties for the first year.

As it now stands, beneficiaries who don't join a Part D plan by the deadline but do so in the future will have to pay an additional 1 percent of premium per month for every month they weren't enrolled. For example, someone who doesn't join by May 15 but does in November, when enrollment into the Part D plans opens again, would pay a penalty of 6 percent of premium every month.

Part D premiums for individuals currently average about $32, so the impact of such a penalty might not be that great initially. But premiums will probably increase over time.

"For someone who can stay in a pharmaceutical assistance program, I would hold off switching as long as I can," said Kellie Wild, executive director of the Rx Council of Western Pennsylvania. "But they have to look at: What if the pharmaceutical company pulls the plug on the program in the future and then I have to pay the penalty for Part D?"