The organisation Boy Scouts of America (BSA) has unanimously voted in favour of allowing gay adults to serve as leaders.
Officials say it will lift a ban on gay leaders in what is a major step towards dismantling a policy that has caused deep rifts in the 105-year-old organisation.
The resolution will allow individual branches to select adult leaders without regard to sexual orientation.
The group's National Board will meet to ratify the resolution at the end of the month.
In 2013, the BSA voted to end a ban on allowing openly gay boys to become scouts.
Earlier this year, former US defence secretary Robert Gates, who is BSA president, told the group's national meeting that the ban on gay adults needed to end, saying it was no longer sustainable.
The selection of Mr Gates as president in 2014 was seen as an opportunity to revisit the policy since he helped end the "don't ask, don't tell" policy that barred openly gay people from serving in the US military.
The resolution, which was passed by the BSA's 17-member executive committee on Friday, will become official policy if it is ratified by the 80-member executive board later this month.
It will allow scout units to set their own policy on the issue and mean they can select adult leaders without regard to sexual orientation.
It will, however, also allow units with religious ties to "continue to choose adult leaders whose beliefs are consistent with their own".
Several denominations that sponsor large numbers of scout units - including the Roman Catholic Church and the Southern Baptist Convention - have been apprehensive about ending the ban on gay adults.
The resolution was hailed by Zach Wahls, an Eagle Scout (the highest boy scout rank) raised by two lesbians who now heads the advocacy group Scouts for Equality.
"While this policy change is not perfect - BSA's religious chartering partners will be allowed to continue to discriminate against gay adults - it is difficult to overstate the importance of today's announcement," Mr Wahls said.