Agencies were recently expected to put together lists of all positions they intended to convert into the new employment classification. But according to the Office of Personnel Management’s Feb. 6 final rule, those conversions can only be formalized once President Donald Trump orders it.

OPM’s regulations last month set off a one-month countdown before the president would be able to sign an executive order, officially converting federal positions to the new schedule. The 30-day deadline is set for March 9, making that date the earliest employee conversions could begin occurring.

It’s not yet clear how many federal positions will be affected. OPM estimated about 50,000 employees would be placed into Schedule Policy/Career. But plaintiffs in a recent lawsuit warned that the number could ultimately be much higher.

“The lack of any limiting principle as to which positions the president can move (both now and in the future) effectively means the entire career civil service is at risk,” the plaintiffs wrote.