Mount Vernon Square is a Washington Metro station in Washington, D.C., on the Green and Yellow Lines. During rush hours, this is the northern terminus for Yellow Line service to Huntington, and trains reverse direction using a pocket track just north of the station. Metro has been running off-peak and weekend Yellow Line trains north to Fort Totten since 2006, and three rush hour only Yellow Line trains per hour between Greenbelt and Franconia-Springfield as part of the Rush Plus service pattern, which began on June 18, 2012. Mount Vernon Square is the least-used station within the Metro system's core section, seeing only 3,813 entries each weekday.