(Bloomberg) -- Gay men in the U.S. will be able to give blood under new guidelines finalized by the Food and Drug Administration, reversing a three decade-long ban that prohibited men who have sex with men from donating.

Men who have sex with men now must wait a year after sexual contact with another man before giving, according to the FDA guidance released Monday. The guidelines come almost a year after the FDA said it would recommend the change.

“We have taken great care to ensure this policy revision is backed by sound science and continues to protect our blood supply,” acting FDA Commissioner Stephen Ostroff said in a statement.

Since 1983, men who have had sex with other men have been banned by the U.S. from donating blood because of the concern that HIV could be transmitted to recipients during surgery or other medical procedures when the blood is used. Blood banks now test blood for HIV, though even with current technology the virus isn’t usually detectable in the first nine to 11 days after infection. Several countries, including the U.K. and Australia, have one-year deferrals as well. Studies in Australia have shown no change in risk to the blood supply, the FDA said.

To contact the reporter on this story: Anna Edney in Washington at aedney@bloomberg.net To contact the editors responsible for this story: Crayton Harrison at tharrison5@bloomberg.net Drew Armstrong, John Lauerman