The Boy Scouts of America (BSA) says its decision to allow gay scouts cannot necessarily explain the reason for a fall in members.
Numbers are down 6% – however the organisation has recorded similar year-on-year falls over the past decade.
A ban on openly gay adult scout leaders and volunteers remains in place.
The Associated Press reports BSA spokesman Deron Smith as saying that it was “impossible” to know if the new policy had contributed to a decline.
“There are many factors that go into a family’s decision to join scouting and it’s impossible to point to any single factor that influences our membership numbers,” Mr Smith said in an email.
“This includes, but is not limited to, the limited amount of discretional time and parents wanting relevant programs for their kids.”
Defending the new rules, he added that accepting openly gay boys “allows us to serve more kids.”