The Sibley Hospital–Stadium Armory Line, designated Route D6, is a daily bus route operated by the Washington Metropolitan Area Transit Authority between Stadium–Armory station of the Blue, Orange, and Silver Lines of the Washington Metro and Sibley Hospital in the Palisades neighborhood.

Route D6 operates daily between Stadium–Armory station and Sibley Hospital connecting Palisades, Foxhall, Burleith, Georgetown, and Kingman Park residents to Downtown without having to take the train.

[3] Route D6 originally began operating between Glover Park and Downtown under the Capital Street Company.

On June 15, 1977, route D6 was extended from Rhode Island Avenue to Washington Hospital Center.

A new route D8 was also introduced to operate between Washington Hospital Center and Sibley Hospital via the Hospital Complex, Trinity University, Glenwood Cemetery, the Edgewood Terrace Apartments, the Rhode Island Avenue Shopping Center, the Rhode Island Avenue–Brentwood station, Washington Union Station, Judiciary Square, Metro Center, and Dupont Circle stations.

Eastbound short trip buses to Stadium Armory will leave Farragut Square (on 17th Street) at 3:14, 3:39, 4:02, 4:25, 4:45, 5:09, 5:32, 5:54, and 6:13 p.m.

[9][10] During the COVID-19 pandemic, the route was reduced to operate on its Saturday supplemental schedule during the weekdays beginning on March 16, 2020.

There would be no alternative service between Dupont Circle and Farragut Square, MacArthur Boulevard, or to Stadium Armory station.