Maryland Code, State Personnel and Pensions § 7-402

(a) Each employee subject to this subtitle is required to complete a 6-month probationary period as the final step in:

(b) An employee is not required to serve a probationary period if the employee is reinstated within 1 year after the employee's separation from State service to a classification in which the employee had previously completed a probationary period.

(c) To successfully complete a probationary period, an employee is required to demonstrate proficiency in the assigned duties and responsibilities of the position to which the employee is appointed.