The Bush administration does not have the authority to extend the May 15 enrollment deadline for everyone eligible for the new Medicare prescription drug benefit, an official said Friday.

``It's legally not permissible,'' said Leslie Norwalk, deputy administrator of the Center for Medicare and Medicaid Services.

Some advocacy groups and Democratic lawmakers are pressing the Bush administration to let all Medicare beneficiaries sign up for the new drug benefit after May 15, just as the administration is doing for some low-income people.

Under the law establishing the drug benefit, the secretary of the Department of Health and Human Services can call for extending open enrollment into Medicare Part D by declaring a ``special enrollment period'' for exceptional circumstances.

In early April, HHS said people who qualify for the low-income subsidy meet that exceptional circumstance, and they will be allowed to enroll in plans after the May 15 deadline. Those seniors must have an income below 150 percent of the poverty line and have limited assets.

The exception, Norwalk estimates, could affect about 2 million people. But to grant that exception to all 43 million eligible Medicare beneficiaries ``undermines what Congress put into place.''

However, Rep. Rahm Emanuel, D-Ill., said the logic the administration used to grant an exception for low-income seniors should apply to all Medicare beneficiaries.
``If a delay in the enrollment deadline is good enough for low-income seniors, it is good enough for all seniors - regardless of income,'' Emanuel said.