AS THE SENATE weighed whether to proceed to debate on health-care reform, we hoped lawmakers would take up an imperfect measure and improve it. So far they've done one but not the other. The first week and a half of debate has largely consisted of window-dressing Democratic amendments that win approval and Republican amendments designed to derail the entire enterprise that fail to get 60 votes. Now, however, there are hopeful signs of changes that would improve the measure, particularly on the central question of controlling health-care costs -- along with other, more worrisome developments.

The best news so far is a package of changes assembled by Virginia Democrat Mark Warner and 10 other freshmen senators. These could be stronger, but they push in the direction of faster transformation in the way health care is delivered. For example, the underlying bill would have Medicare pay some providers based on the quality of their performance; the Warner package would expand that to include hospices, ambulatory-care centers, psychiatric hospitals and others. The underlying bill calls for pilot projects to create so-called accountable-care organizations, which more closely monitor the health of beneficiaries; the Warner package would push for more such projects sooner and allow for more flexibility in deciding how to structure them.

The underlying bill would create pilot programs for "bundling" payments to providers for treating certain illnesses; the Warner package would expand the number of conditions covered. The underlying bill would create an Independent Medicare Advisory Board to make cost-cutting recommendations, subject to fast-track congressional approval; the Warner package would expand the commission's mandate to include recommendations for the private sector as well, although its recommendations would not be binding. These are all steps in the right direction.

However, there is more to be done and remaining cause for concern about some of the provisions in the Senate bill. The Medicare commission should not only be expanded, it should be unshackled; as currently drafted, it could not recommend modifying eligibility or benefits for Medicare recipients, nor could it urge changes in payment rates for hospitals, physicians, hospices and suppliers of durable medical equipment. There are legitimate concerns about whether the individual mandate to purchase health insurance is backed by tough enough penalties for those who fail to comply. To deal with the risk that individuals will game the system by waiting until they get sick to purchase insurance, lawmakers should consider imposing a waiting period -- as Medicare does -- between signup and eligibility for benefits. Prohibiting illegal immigrants from buying insurance on the newly created exchange with their own money, as the Senate bill now does, is irrationally punitive: Lifting this restriction would bring more, mostly younger and healthier, enrollees into the system, and reduce the costs resulting from uninsured immigrants ending up in emergency rooms.

The creation of a new program for long-term care insurance has not received nearly enough attention; the program runs the risk of becoming a drain on the Treasury, as the 51 to 47 Senate vote to strip the provision from the bill illustrates. (The amendment required 60 votes to succeed, but it is telling that 11 Democrats and Independent Joseph I. Lieberman of Connecticut voted in favor.) Dealing with long-term care is a significant concern, and lawmakers have taken pains to limit the government's financial exposure. Nonetheless, if premiums become too costly or benefits turn out to be inadequate, there will be pressure for the government to solve the problem -- by opening a checkbook that is already overdrawn.