Former Pres. Donald Trump put the controversial ban in place in 2017. The ban reversed the Obama administration's policy to open service to transgender people.
READ MORE: Trump bans transgender individuals from armed forces
"The ban will be officially lifted tomorrow," said one of the individuals familiar with the matter to ABC News.
New Defense Secretary Lloyd Austin will attend the White House ceremony on Monday where the executive order will be signed.
READ NEXT: Effect of US military ban on transgender troops remains to be seen