(CNN) - The US military has issued new guidance on how transgender individuals will be admitted to the armed services in the new year.
Transgender service members are challenging President Donald Trump's memorandum directing the secretary of defense to bar transgender Americans from military service. The challengers have so far been successful in blocking the President's policy from going into effect while the lawsuit plays out in court.
The Pentagon is proceeding with plans to accept transgender applicants to the military on January 1 after a federal judge declined earlier this month to put the deadline on hold, the Justice Department has appealed that ruling.
The new memorandum which is dated December 8 "provides interim policy guidance for processing transgender applicants for military service" to all military processing commands detailing how they should treat and evaluate transgender recruits.
"The new standard permits accession of qualified transgender applicants," the memo says, adding that implementation of the new standard is "mandatory" starting January 1, 2018.
The seven-page guidance is written by Navy Capt. David Kemp, commander of US Military Entrance Processing Command, and offers detailed instructions on how a transgender recruits' gender should be listed on forms, saying all "transgender applicants will be addressed by their preferred gender name and pronoun." It also provides guidance as to what underwear recruits should wear during screening.
For any applicant who has undergone sex reassignment surgery or a medical treatment plan, the recruit will need to have been "stable" in their new gender for 18 months prior to entering the military.
The memorandum defines "stable" as "medical and surgical interventions for gender transitions are complete with the exception of continued use of stable cross-sex hormone protocol, if applicable, no functional limitations of complications persist, and the individual is not experiencing clinically significant distress or impairment in social, occupational, or other important areas of functioning."
If a recruit identifies as transgender but has not undertaken legal or medical steps, they will be asked to return after they have.
Speaking last week, Defense Secretary James Mattis said the Pentagon was still awaiting the results of the court action to determine what policy to go with.
"I've got to wait until the court issues are resolved," Mattis said. "I don't want to say something now. You know, obviously we have an independent judiciary, and I've got to leave them independent for right now until they get done."