News yesterday that earlier cost estimates for the Medicare Modernization Act were in fact low caused many members of Congress to demand changes in the law.

In January 2004, less than two months after Mr. Bush signed the law, the White House said it would cost $534 billion from 2004 to 2013. Of that amount, $511 billion was specifically for the drug benefit. For the same 10-year period, the administration now puts the cost of the drug benefit at $518 billion.

Lawmakers have begun reviving many of the issues they sparred over during the 2003 debate that led to enactment of the law. Members are looking at several options: imposing a cap on spending for the drug benefit, cutting the federal subsidy for wealthy beneficiaries, requiring the government to negotiate prices with drug manufacturers, legalizing imports of lower-cost medicines from Canada and other countries, and prohibiting Medicare coverage of “lifestyle drugs”.

Fiscal conservatives have said that they want to cap the cost of the drug benefit at $400 billion and have suggested that Congress rewrite the law to focus resources on low-income people who really need the help. The new drug coverage will be available to all 41 million Medicare beneficiaries, regardless of their income or assets.