Maryland Code, Land Use § 23-205

(b)(1) The county planning board shall approve or disapprove a preliminary subdivision plan within 70 days after the complete plan application 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:

(3) The 70-day time period under paragraph (1) of this subsection does not include:

(c)(1) Each office to which the county planning board refers a preliminary subdivision plan shall return to the county planning board one copy of the plan and any comments noted on it within 30 days after the referral.

(2) If an office does not reply in accordance with paragraph (1) of this subsection, the plan shall be considered to be approved by the office.