WASHINGTON – A bipartisan group of senators that includes Republican Sen. Olympia Snowe of Maine said Wednesday it would work to reimburse states for expenses incurred because of problems with the new Medicare drug benefit.

The federal government took on the responsibility Jan. 1 of subsidizing prescription drug costs for low-income seniors and the disabled, which previously occurred through Medicaid, the health insurance program for the poor.

But some people have had trouble getting their medicine during the transition, so many states have stepped in to help pay for it.

“The unexpected costs to the states will likely be in the hundreds of millions of dollars,” 14 Democratic governors said in a letter sent to President Bush on Tuesday.

The governors, including Maine Gov. John Baldacci, asked the president to have the federal government fully reimburse the states and to investigate the underlying causes of the transition problems.

At least five senators plan to sponsor a bill that would reimburse the states for 100 percent of their costs plus interest. The legislation also directs the secretary of Health and Human Services to recover overpayments to private prescription drug plans and return that money to Medicare.

“While there are many problems that need to be dealt with regarding the implementation of this drug plan, it is critical that we pay these states back as soon as possible,” said Sen. Frank Lautenberg, D-N.J.

Other co-sponsors include Norm Coleman, R-Minn., Charles Schumer, D-N.Y., and Dianne Feinstein, D-Calif.

The administration has said it will work with states to ensure that the private plans offering drug coverage reimburse states. Health and Human Services officials acknowledge there have been some problems with the program, but say it is working well for the large majority of participants.