Md. Code, State Personnel and Pensions § 24–302

(a) Subject to subsections (b) and (c) of this section, the Board of Trustees shall adopt regulations that specify the period of employment in a year that is equal to 1 year of service credit.

(b) The Board of Trustees may not allow more than 1 year of service credit for a calendar year.

(c) A member is entitled to receive 1 month of service credit for employment for a month or a part of a month if a member contribution is made in that month.