The scheduled closures will impact stations between Sullivan Square and Tufts Medical Center beginning each Friday night at 8:45 p.m. from January 17 through February 16.
During the closures, the MBTA says Orange Line fares are being waived.
Workers will be replacing the Orange Line station track in both directions at North Station, and they'll be working on the track at State, Haymarket, and Downtown Crossing Stations.
It's all part of the MBTA's ongoing $8 billion 5-year capital improvement program, which is focused on improving the T's safety and reliability. After the track work is complete, the MBTA says there will be typical speed restrictions in place as a safety precaution.
If you're planning to head northbound on the Orange Line over the next four weekends, passengers can exit at Back Bay Station and head 0.2 miles over to Copley Station. There the Green Line is running over to Haymarket, where there will be shuttle buses to Sullivan Square.