The Food and Drug Administration yesterday classified acupuncture needles as medical devices for "general use" by trained professionals.

The agency did not go so far as to state that acupuncture is effective for any particular condition, an outcome many acupuncturists had hoped for. But by designating instruments of a 2,000-year-old Chinese healing art in the same category with such standard Western medical tools as scalpels and syringes, the FDA removed a major barrier to insurance coverage for acupuncture treatments.

"It's a very wise and logical decision," said Wayne B. Jonas, director of the Office of Alternative Medicine at the National Institutes of Health in Bethesda, which sponsors research on acupuncture. "I'm glad they did it."

More than two dozen states and the District of Columbia have legalized acupuncture, and an estimated 15 million Americans have tried it for a variety of conditions including chronic pain, nausea, digestive problems and drug addiction. Practitioners insert flexible needles into the skin at specific points, then twist them to enhance the flow of a hypothetical "energy" in the body.

Until now, however, acupuncture needles have been classified as Class III medical devices, meaning their safety and usefulness was so uncertain that they could only be used in approved research projects. Because of that "experimental" status, many insurance companies -- as well as Medicare and Medicaid -- have refused to cover acupuncture.

Although FDA officials are aware that most acupuncture treatments in this country are not part of any formal experimental protocol, they have for years turned a blind eye to such infractions. But in December 1994, a team of lawyers and acupuncturists formally asked the FDA to approve the needles for the treatment of five conditions: pain, nausea and vomiting, substance abuse, asthma and other respiratory conditions, and stroke and paralysis.

Scores of scientific studies were submitted with the application to bolster claims that acupuncture was a safe and effective treatment for those ailments.

"We reviewed their petition and said there is some suggestion that acupuncture works for these specific claims but it doesn't reach the level of proof we generally require," said Bruce Burlington, director of the FDA's center for devices and radiological health. "But we did conclude that a substantial number of states regulate acupuncture as a healing art, and within the context of acupuncture as a healing art we can ask, do these needles break, do they cause infections, and do they work as a tool for the art of acupuncture?"

In the end, Burlington said, the agency decided that acupuncturists themselves -- not the needles they use -- should be the main focus of regulatory efforts. "We don't ask, Does gall bladder surgery work?' " he said. "We ask, Can a knife make an incision?' So it didn't require us to establish that acupuncture works, but that needles work in acupuncture."

Under the terms of the FDA decision, the needles will be designated as Class II medical devices and manufacturers will have to submit documentation detailing the materials used and other specifications. The needles must be labeled as "single use only," which means they must be discarded after use to prevent the spread of infection from one patient to another. They also must bear a prescription labeling statement that restricts their use to qualified practitioners, the definition of which varies from state to state. No American company manufactures acupuncture needles; most are imported from Asia.

"This is historic," said Hannah Bradford, a local acupuncturist and board member of the Society for Acupuncture Research in Bethesda. "It removes one of the big blocks for private insurance and I think it may remove a block for federal employees and Medicare coverage."

Dan DiFonzo, a spokesperson for the Health Insurance Association of America, said it was too soon to say whether the FDA ruling would open the door to widespread coverage for acupuncture. But in general, he said, "when the FDA . . . determines that devices are necessary or generally effective, then they are usually reimbursable by insurance."

James S. Turner, the District attorney who helped lead the petition effort, said he expected to see expanded coverage. "This paves the way for insurance companies to say we will reimburse for acupuncture as long as it is being practiced by a state-recognized acupuncturist," he said.