In meetings over the last nine months, advocates for hepatitis patients have urged the Obama administration to issue guidance to state Medicaid directors on appropriate coverage of the new drugs, but federal officials have been noncommittal.

“States have flexibility to determine the best way to manage their Medicaid benefits, including drug benefits,” said J. Timothy Gronniger, a senior official at the federal Centers for Medicare and Medicaid Services who worked at the White House until recently.

Other administration officials said they wanted to ensure access to the new hepatitis drugs, but also had to consider the financial effect on the federal government, which pays at least half of the cost for Medicaid patients in every state.

Moreover, federal officials said they were being cautious because any directives for Medicaid coverage of hepatitis drugs could set a precedent affecting new drugs for other conditions, and many expensive drugs are in the pipeline.

The administration of President Bill Clinton took a more aggressive stance in 1996, when states were limiting access to a new generation of potent but costly drugs for H.I.V. and AIDS.

The Clinton administration told state Medicaid directors that they had to cover the new AIDS drugs, known as protease inhibitors. States could impose certain limits on use of the drugs, but the limits must not “excessively or unreasonably restrict coverage of effective treatments” for people with H.I.V. and AIDS, the Clinton administration said.

Cindy Mann, the top federal Medicaid official from 2009 to January of this year, said there was “an increasing consensus among health care professionals” about the circumstances in which the new hepatitis drugs should be provided. But this consensus is not reflected in state policies, she said, so the federal government “needs to provide some guidance and clarification” to states.