The agency had previously taken down similar guidance last month, saying at the time that it was posted in error.
The CDC sent out a press release on Monday to highlight the updated guidance on its "How COVID is Spread" website.
In a statement, the agency wrote, "CDC continues to believe, based on current science, that people are more likely to become infected the longer and closer they are to a person with COVID-19. Today’s update acknowledges the existence of some published reports showing limited, uncommon circumstances where people with COVID-19 infected others who were more than 6 feet away or shortly after the COVID-19-positive person left an area."
The CDC said warns that virus transmission can occur in poorly ventilated and enclosed spaces, and where people are involved in activities causing heavy breathing. Singing and exercising were the two activities the CDC highlighted in the release. Actions like these add to the accumulation or "buildup" of virus-carrying particles in the air, the CDC said.
The agency said its recommendations for stopping the spread of coronavirus remains the same: wear a mask that covers the nose and mouth, stay at least 6 feet away from others, wash hash frequently and stay home if you're sick.
The agency, long held up as a power at the forefront of fighting disease outbreaks inside the U.S. and internationally, is dealing with a crisis of its own now. A series of external attacks and mess-ups in recent weeks had bogged the agency down as it soon faces a hard fought coronavirus vaccine campaign.