South Shore Line officials have announced the extension of the Buy One Get One ticket promotion for September.
Officials say all monthly tickets bought for September will remain valid for the month of October.
They say those with a paper monthly ticket should plan to keep and use it through the month of October while passengers using a digital monthly ticket on the app will see an October ticket uploaded to their accounts.
Passengers who receive tickets through an employer benefit program should not order their October tickets if they receive a September monthly ticket.