The guidance applies to men who have lived in or traveled to Miami-Dade, Broward and Palm Beach counties since June 15. There are 12 sperm donor banks in those counties, the Associated Press reported.
Mosquitoes are the main cause of Zika infection in people, but it can also be spread through sex. Not all people infected with Zika get sick, and the virus can remain in semen for months.
The CDC said there are no confirmed cases of a sperm donation causing Zika infection in a pregnant woman, and the risk is considered low, the AP reported.
Zika infection during pregnancy can cause severe brain-related birth defects.
While Zika can be detected in blood donations, there is no good test for Zika in semen, according to the Food and Drug Administration. That agency regulates sperm donations and previously warned sperm banks not to accept donors who have been diagnosed with Zika or been to an area where Zika is common in the past six months, the AP reported.
The last mosquito Zika transmission in Florida was in December, but officials believe mosquitoes will start spreading the virus again this summer.
Last year, 221 people in the continental U.S. got Zika from mosquitoes, and most of those cases were in the Miami area. There is no evidence that mosquitoes in Broward or Palm Beach were spreading Zika, and officials believe infections in those counties occurred in Miami-Dade, according to Dr. Denise Jamieson, head of the CDC's Zika emergency response.
"A lot of times people may not realize when they crossed the county line," she told the AP.