Maryland Code, State Personnel and Pensions § 22-303

(1) for employment as a member;

(2) transferred from a retirement or pension system under Title 37 of this article or Title 31, Subtitle 1 of this article;

(3) for military service, as provided in Title 38 of this article;

(4) purchased under this subtitle; and

(5) that equals, for a member who has transferred between the Employees' Retirement System and the Teachers' Retirement System, the member's eligibility service recognized under the previous system through the date before the member became a member of the current system.