MARC Email alert came in today:
MARC Penn Line passengers who transfer to the Washington Metrorail Orange Line at New Carrollton should note that the Orange Line will be closed from New Carrollton to Stadium Armory station May 28 to September 5. MARC passengers will not be able to transfer to Metrorail trains at New Carrollton.
Passengers who transfer to Metrorail at New Carrollton should visit the WMATA website for a list of travel alternatives: www.wmata.com/initiatives/plans/PlatformProject