Md. Code, Land Use § 23-201

(a) (1) The appropriate county planning board shall approve or disapprove a subdivision plat within 30 days after the plat is submitted to the county planning board. (2) If the county planning board does not take action in accordance with paragraph (1) of this subsection: (i) the plat shall be considered approved; and (ii) the county planning board shall issue a certificate of approval on demand. (3) An applicant may consent to an extension. (b) A plat submitted to the county planning board shall contain the name and address of a person that may be sent notice of a hearing. (c) (1) The county planning board shall hold a hearing before taking action on a subdivision plat, unless: (i) the county planning board approves the plat exactly as the plat was submitted by the applicant to the county planning board; or (ii) the applicant waives the hearing requirement in the application. (2) At least 5 days before a hearing, the county planning board shall send notice of the hearing to the address included with the plat in accordance with subsection (b) of this section. (3) Subdivision regulations may include provisions for: (i) notice to owners of properties that would be substantially affected by approval of a subdivision plat; (ii) public hearings on the applications; and (iii) an appeal to the district council from a decision approving or disapproving a subdivision plat. (d) The grounds for disapproval of a plat shall be stated on the records of the county planning board.