Article 115 of the Uniform Code of Military Justice (UCMJ) deals with malingering. Although it's sort of an outdated word, malingering is a serious offense in the military. It means you're pretending to do the job you're assigned instead of doing it. Malingering carries serious penalties which vary based on specific factors.
According to the UCMJ:
The essence of this offense is the design to avoid performance of any work, duty, or service which may properly or normally be expected of one in the military service. Whether to avoid all duty or only a particular job, it is the purpose to shirk which characterizes the offense. Hence, the nature or permanence of a self-inflicted injury is not material on the question of guilt, nor is the seriousness of a physical or mental disability which is a shame.
What Constitutes Malingering in the Military
Being found guilty of malingering depends on a few factors. If you know you're assigned to a specific duty—or area of work—and pretend to be sick or injured, or if you intentionally hurt yourself to avoid that duty, then you fit the criteria of a malingerer.
The UCMJ states:
“Any person subject to this chapter who for the purpose of avoiding work, duty, or service”—
(1) feigns illness, physical disablement, mental lapse or derangement; or
(2) intentionally inflicts self-injury; shall be punished as a court-martial may direct.
(1) That the accused was assigned to or was aware of prospective assignment to, or availability for, the performance of work, duty, or service;
(2) That the accused feigned illness, physical disablement, mental lapse or derangement, or intentionally inflicted injury upon himself or herself; and
(3) That the accused’s purpose or intent in doing so was to avoid the work, duty, or service. Note: If the offense was committed in time of war or in a hostile fire pay zone, add the following element
(4) That the offense was committed (in time of war) (in a hostile fire pay zone).
Punishment for Malingering
Depending on the nature of the offense, there's a range of punishment for malingering. If it can be proven that the accused person intentionally injured himself, or pretended to be injured, that's the baseline. If the acts happened during wartime or a hostile war zone, the punishments are more severe.
According to the UCMJ, feigning an injury will get you a dishonorable discharge and one-year confinement, during which you'll forfeit all pay and allowances.
Feigning injury during wartime or in a hostile war zone will result in a dishonorable discharge, forfeiture of pay, and three-year confinement.
For intentionally injuring yourself, which can range from violently hurting yourself to starving yourself to get out of work, you can expect a dishonorable discharge, forfeiture of pay, and five-year confinement. If you intentionally injure yourself during war or in a hostile zone, you'll be confined for ten years and be dishonorably discharged.