Maryland Code, Local Government § 13-906

(b)(1) A building code adopted under this section may incorporate by reference all or part of a code proposed by any governmental unit or a trade or professional association for general distribution in printed form as a standard model on any subject relating to constructing, maintaining, or repairing buildings or structures.

(2) Any later amendment to a code or part of a code that is adopted by reference is not effective until the County Commissioners of St. Mary's County incorporate the specific amendment into the county's building code.