The "Don't ask, don't tell" policy banning open homosexuality in the United States military has been repealed after nearly two decades.
Service members can now reveal they are gay without fear of investigation or discharge, the BBC reports.
"Repeal Day" parties have been organised across the country to mark what is seen as a victory for gay rights.
Congress voted last year to repeal the law, which was introduced in 1993 under the Clinton administration. It allowed gay people to serve so long as they did not openly acknowledge their sexual orientation, while commanders were not allowed to ask.
The armed forces have been accepting applications from openly gay recruits for a number of weeks and will begin processing them now that the new law has taken effect.
Those who were discharged under the "Don't ask, don't tell" rule are entitled to re-enlist.
But existing standards of personal conduct, such as those pertaining to public displays of affection, will not change.
