BALTIMORE, JULY 21 -- Blue Cross and Blue Shield of Maryland, seeking to dispel fears among 1.6 million customers that they could lose their policies if they develop AIDS, formally announced today it considers AIDS a disease like all others that is covered by Blues insurance.

Stating publicly what they say has been their internal practice since AIDS became a nationally recognized phenomenon in 1984 and 1985, Blues officials also said they will not require AIDS blood tests for either current or future group or individual customers as a condition for insurance.

"We're putting this on paper so that . . . everyone will know just how we're going to treat AIDS," said Arthur T. Keefe, medical director of the Maryland Blues, the largest health insurer in the state.

"Our rule of thumb is: it's exactly like any other disease," he explained, " . . . and we will provide the same kind of coverage as for all other diseases."

Continued coverage for AIDS patients -- about 300 out of 1.6 million customers -- will not affect insurance premium costs, at least for now, Keefe said in an interview. The numbers are "are minuscule" now, he said, but if the AIDS population balloons in the 1990s, as some medical experts predict, premium costs could go up.

There have been more than 1,100 cases of AIDS reported in Maryland, Virginia and the District since 1982, according to health officials.

Representatives for other nonprofit Blue Cross-Blue Shield organizations, including the one for the Washington area, as well as profit-making commercial insurance companies elsewhere across the country, said their policies toward AIDS are generally the same as the Maryland Blues'. But few if any have issued similar public position papers.

Some, such as Blue Cross and Blue Shield of the National Capital Area in Washington, said they have found little need for a public pronouncement.

"We haven't had any great outbreak of concern here," said Raymond Freson, manager of the Washington area Blues, covering 1.1 million customers in the District, Northern Virginia and Prince George's and Montgomery counties in Maryland. Freson speculated that recent public hearings in both the D.C. Council and Congress on health and privacy protections for AIDS patients have heightened public awareness on the subject in the Washington area.

But Keefe said a large volume of calls and letters expressing fear and confusion prompted the Maryland Blues to formulate a public policy statement. The Maryland Blues offer insurance throughout the state except in Montgomery and Prince George's counties.

"People were afraid," Keefe said, "that for some weird and arbitrary reason, they would lose their coverage if they were diagnosed as having AIDS. It was scaring people."

Today's public pronouncement, he said, "reinforces longstanding corporate positions prohibiting discrimination against any particular disease or group of customers."

Gay rights organizations, whose members compose one of the highest AIDS risk groups, expressed approval of the announcement.

"We're obviously quite pleased," said Jeff Levi of the National Gay and Lesbian Task Force in Washington. "It was a very responsible position to take."

The Maryland Blues' announcement also said the company will award education and research grants on AIDS and will give "individual case management," or specialized treatment, to AIDS patients to "assure that high quality, cost-effective care is provided."

In addition, Keefe said, the organization will pay for AZT and other experimental drugs authorized by the U.S. Food and Drug Administration for treating AIDS.

"Ordinarily, we do not pay for experimental drugs," he said, "but because of the seriousness of AIDS . . . we're willing to do it."

Keefe cautioned that there are two conditions under which insurance coverage is not be available: When applicants request insurance and acknowledge that they have AIDS. "That's like selling house insurance when the house is on fire," Keefe said.

When insured members are found to have AIDS after joining the Blues but the condition existed before they joined. Such members would be ineligible for coverage for nine months after joining but would regain eligibility after that period. This policy applies to other serious conditions, such as heart disease, Keefe said, and is not designed to single out AIDS patients.

Of the 621 AIDS cases reported in Maryland by state health officials in the first half of 1987, Keefe estimated, the Maryland Blues are providing coverage for about half, or a little more than 300.

He did not have cost figures for AIDS patients here, but said the average medical cost in New York and California for an AIDS patient is about $70,000.

"As far as we know," he said, "it's a 100 percent fatal disease."

Public health officials have predicted the number of AIDS patients in the United States, currently about 34,000, could jump to 270,000 by 1991, pushing the cost to treat them from $1 billion to $20 billion, according to Maryland Blues figures.

If that happens, insurance premiums also could jump, Keefe said. "There's no free lunch," he said.

In the meantime, the development of a vaccine or other medical breakthrough to stop the spread of acquired immune deficiency syndrome could occur, stemming the costs for AIDS. "That's the real hope we all have," Keefe said.