Time is running out for first term and career Marines in just over 40 military occupational specialties to secure selective re-enlistment bonuses.

Officials with Manpower and Reserve Affairs released the trimmed list Wednesday. First term Marines in 32 jobs and career Marines in 11 have until March 6 to re-enlist before losing out on a bonus.

The occupational specialties for less experienced Marines include postal clerks, machinists, airframe mechanics for the F/A-18 Hornet, and ammunition and small arms repair technicians. For career Marines — those with six to 10 years under their belts — it is jobs like aviation operations and contingency contract specialists that are on the chopping block.

The full list is available in administrative message 105/15.

Manpower officials employ re-enlistment bonuses as a force shaping tool. As the Corps shrinks from its wartime high of 202,100, the cash payouts — or lack thereof — are used to encourage Marines to exit the Corps or switch out of an overcrowded MOS occupational specialty.

The supply of dollars for bonuses on the whole has dwindled as the wars in Iraq and Afghanistan waned. The Corps allocated $59 million in fiscal 2014 for re-enlisting Marines, but just $55 million in the next budgetary cycle.

Officials want to bump that pool up to $56 million in the coming fiscal year, according to budget documents. But that depends on whether Congress will approve the Defense Department's budget as is, which ignores spending caps imposed by lawmakers in 2013, likely setting up a contentious fight on the Hill.

The request for more dollars for re-enlistment bonuses comes as the Corps moves to temporarily pause the drawdown. Budget documents cite its adverse effect on small unit leaders while Commandant Gen. Joseph Dunford's planning guidance, released last month, similarly cited a shortage of noncommissioned officers.

While planners originally hoped to have the Corps' strength at 182,000 by the end of fiscal 2015, they now intend to keep the force steady at 184,000 through fiscal 2016.

Still, it's the Marines in understaffed MOSs occupational specialties that can expect to see a windfall. Those include intelligence specialists, reconnaissance, cyber security technicians and air traffic controllers.