Officials said a select group of about 80 customers will test the mobile app starting on Monday on the Kingston/Plymouth, Middleborough/Lakeville and Greenbush regional rail lines.
The app, which allows riders to display tickets on their screens when they board trains, is expected to fully launch later this fall. MBTA said it will be available to iPhone, Android and Blackberry users.
MBTA hopes to reduce the need for additional vending machines at stations, and also to cut cash handling costs.