The controversial change doesn't take effect until next year, but it's already raising concerns about sponsorships and even membership.
"We definitely see it as a step in the right direction," said Josh Wynne, who dropped out of the Boy Scouts at the age of 15.
Wynee said he was uncomfortable with his sexuality and the homophobia he says plagued the organization.
The ban on gay adults still stands, which is why Wynne calls the decision only a partial victory.
"The problem is that once a scout member turns 18 they are no longer seen as adequate to be a leader in perhaps the troop that they just were a part of," said Wynne. "So you can see how there is some hypocrisy that lies within the decision."
As supporters celebrate the landmark decision, opponents fear backlash from parents pulling their kids out, to religious organizations cutting off funding. By one estimate, up to one in 10 scouts could leave the program.
Seventy percent of troops are sponsored by churches. Many of which oppose the change.
"The standard is being changed, and if you lower the standard then what's the point in having the Boy scouts at all," said prominent anti-gay rights activist Dr. Patrick Wooden.
Wooden serves as pastor of the Upper Room Church of God in Christ in Raleigh. At one time, his congregation donated $5,000 to the Boy Scouts to help them keep the ban on openly gay youth. He says he won't be backing the Boy Scouts in the future.
"This would be something that I know that I could not support," said Wooden," because it's going to, whether they want to admit it or not, it's going to fundamentally change the Boy Scouts of America.
Wooden says it's only a matter of time before more churches pull their support too.