The expansion of the service, which was put on hold in 2008, is the result of the new transportation package signed by Gov. Martin O’Malley on Thursday.
MARC has only run Monday through Friday since its inception in the 1980s.
Maryland Transit Administration spokesman Terry Owens said the agency is negotiating with Amtrak – the company that owns the track on which the Penn Line operates – to find space in the weekend schedule to allow MARC trains to run.
MTA officials say they hope to offer eight round trips on Saturdays and Sundays.
The expansion will offer extra weekday runs on the Camden Line as well.
The exact date for the additional service wasn’t announced.