Maryland Code, State Finance and Procurement § 7-307

(a) Unless the State budget expressly provides otherwise, whenever a new or substantially renovated facility does not begin operation on the date that was used to determine the amount of the appropriation to the facility in the State budget, the part of the appropriation for operating expenses that is not needed to provide services to the same clients, students, patients, or incarcerated individuals shall revert to the General Fund or to an appropriate special fund and may not be spent for any other purpose or transferred by a budget amendment.

(b) If a facility under this section begins to operate after the date on which the appropriation was based but in the same fiscal year, the Department of Budget and Management shall determine, on a pro rata basis, the amount of the appropriation for operating expenses that shall revert to the General Fund.