Maryland Attorney General Stephen H. Sachs, in what he said is an effort to stem spiraling health costs, today asked the federal government to provide massive files on fees charged by Maryland doctors who treat Medicare patients.

The unusual request, according to several government observers, could trigger lengthy court litigation and a bruising state-federal confrontation over access to public documents in the sensitive area of doctor's fees.

Officials at the U.S. Department of Health and Human Services, which administers Medicare, said some of the information may be confidential and other data may be difficult to cull from the government's maze of computer storage tapes.

The request -- which officials said appeared to be the first of its kind by a state -- also threatens to carry a huge price tag.

Pulling the information together would result in "several extremely large stacks of computer printouts," said Rosario Cirrincione, who works for Health and Human Services' Health Care Financing Administration here. "It would cost thousands of dollars in computer time and reproduction costs."

Sachs countered that he is prepared to go to court to get the files and to press the federal government to pay the bill.

In his formal request under the federal Freedom of Information Act, Sachs asked for two sets of data. One is the "customary charge profile," or median price list, that each doctor charges a Medicare patient for given medical procedures.

The other is for the so-called "prevailing charge screen," a composite of customary charges for specific procedures by all physicians, broken down into geographic areas of the state. Both the customary charge and the prevailing charge are used by HHS to determine Medicare reimbursements to doctors.

There are about 15,000 doctors in Maryland. A majority of them treat Medicare patients, officials said.