Metro-North says service will resume along the length of the Port Jervis line by Nov. 28, a month earlier than expected.
The line serves about 2,800 riders a day in Rockland and Orange counties. It was heavily damaged during the aftermath of Hurricane Irene, with 14 miles of the line knocked out.
Buses have been replacing trains in areas where tracks have not been repaired.
Metro-North had said repairs would be completed in December, but on Monday said service would resume a month earlier than expected.
The full pre-storm schedule of 26 daily trains and 14 trains each weekend day will be back on line Nov. 28.