Md. Code, Public Safety § 13–602

A commission of an officer of the organized militia may be vacated:

(1) on resignation;

(2) through absence without leave for 3 months;

(3) on recommendation of an efficiency board;

(4) under a sentence of a court–martial; or

(5) on conviction of a crime punishable by incarceration for 1 year or more in any state or federal court.