There are several ways one can be kicked out of the Army, including failing physical requirements, going absent without leave and committing gross misconduct. Being kicked out of the Army in this manner is known as an administrative discharge or an involuntary discharge.
Being kicked out of the Army is generally a long and drawn-out process. In the majority of cases, a commander must demonstrate rehabilitative measures before imposing a discharge. This can mean loss of pay, extra duties, certain restrictions or even correctional custody before being kicked out.
Although failing to meet the physical standards set by the Army can ultimately result in being kicked out, it can take many months before a discharge is actually issued. There is also a possibility of discharge action never being initiated; instead, a commander may choose to reassign the soldier to menial work such as digging, painting or cleaning.
Going absent without leave for a few days may seem like an ideal way to get kicked out of the Army, but it doesn't always result in a discharge. If a discharge is initiated, it is likely to be under "other than honorable conditions," which can impact future employment opportunities.
Committing gross misconduct almost certainly results in a discharge, but it is likely to have serious repercussions; there is a high likelihood of trial by court-martial and a resultant criminal record.