The handbook does not mention that beneficiaries face a gap in coverage. After the beneficiary pays a $250 deductible, Medicare pays three-fourths of the next $2,000 in drug costs. But then the beneficiary is normally responsible for all of the next $2,850, and Medicare pays nothing.

The Bush administration is revising a preliminary draft of the 2006 Medicare handbook -- the main tool for educating millions of elderly Americans about the program -- after discovering that many statements in the first draft of the document are inaccurate, misleading or incomprehensible, even to people who have worked on the program for decades.

Members of Congress, insurance companies, advocates for beneficiaries and state insurance regulators all told the Bush administration that the new handbook was flawed.

Gap in Coverage

For example, in describing the drug benefit, the handbook says, "After you meet the deductible, you pay part of the cost of covered prescription drugs, and the plan pays part."

The handbook does not mention that beneficiaries face a gap in coverage. After the beneficiary pays a $250 deductible, Medicare pays three-fourths of the next $2,000 in drug costs. But then the beneficiary is normally responsible for all of the next $2,850, and Medicare pays nothing.

Moreover, the handbook lumped together the traditional government-run Medicare program, which covers 36 million people, and tiny private fee-for-service health plans, in which fewer than 100,000 beneficiaries have enrolled. Both, it says, are "fee-for-service plans, available nationwide."

Inaccurate and Misleading

In fact, the two are fundamentally different. Private fee-for-service plans are available in selected counties from private insurance companies under contract to Medicare, with premiums and co-payments set by the insurers.

By contrast, traditional Medicare is offered by the government throughout the country, with uniform premiums and co-payments set by law. Beneficiaries may have to pay more in some private fee-for-service plans than in traditional Medicare.

Vicki Gottlich, a lawyer at the Center for Medicare Advocacy, a nonprofit group that counsels beneficiaries, said it was "inaccurate and misleading" to emphasize the similarities between traditional Medicare and the private fee-for-service plans.

There Will Be Changes

Gary R. Karr, a spokesman at the Centers for Medicare and Medicaid Services, said the agency was revising the 106-page handbook to address such concerns. The handbook, he said, will include "a more detailed description" of the new drug benefit, including the gap in coverage, and will clarify the differences between traditional Medicare and private plans. The final version will be mailed to beneficiaries this fall.

Dr. Mark B. McClellan, administrator of the Centers for Medicare and Medicaid Services, said the first draft of the handbook was prepared by career employees of the Medicare agency and would be revised to reflect the comments from outside experts. "There will be changes," McClellan said. "We can communicate some things more effectively, more simply and more clearly."